Thin optoelectronic modules with apertures and their manufacture

ABSTRACT

The wafer-level manufacturing method makes possible to manufacture ultrathin optical devices such as opto-electronic modules. A clear encapsulation is applied to an initial wafer including active optical components and a wafer-size substrate. Thereon, a photostructurable spectral filter layer is produced which defines apertures. Then, trenches are produced which extend through the clear encapsulation and establish sidewalls of intermediate products. Then, an opaque encapsulation is applied to the intermediate products, thus filling the trenches and producing aperture stops. Cutting through the opaque encapsulation material present in the trenches, singulated optical modules are produced, wherein side walls of the intermediate products are covered by the opaque encapsulation material. The wafer-size substrate can be attached to a rigid carrier wafer during most process steps.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is the National Stage of International Application No.PCT/SG2017/050194, filed on Apr. 5, 2017, which claims the benefit ofpriority U.S. Application No. 62/319,893, filed on Apr. 8, 2016. Thedisclosure of the prior applications is incorporated herein byreference.

The present disclosure relates to ways of manufacturing optical devicessuch as opto-electronic modules, e.g., proximity sensors, and tocorresponding devices and modules, respectively. The manufacture can bewafer-level large-scale manufacture. The optical devices can be verythin and can include precisely positioned apertures. Correspondingoptical devices can be integrated in, e.g. consumer-oriented productssuch as smartphones, gaming systems, laptop computers, tablets, andwearable technology.

“Wafer”: A substantially disk- or plate-like shaped item, its extensionin one direction (z-direction or vertical direction) is small withrespect to its extension in the other two directions (x- andy-directions or lateral directions or horizontal directions). Usually,on a (non-blank) wafer, a plurality of like structures or items arearranged or provided therein, e.g., on a rectangular grid. A wafer mayhave openings or holes, and a wafer may even be free of material in apredominant portion of its lateral area. A wafer may have any lateralshape, wherein round shapes and rectangular shapes are very common.Although in many contexts, a wafer is understood to be prevailingly madeof a semiconductor material, in the present patent application, this isexplicitly not a limitation. Accordingly, a wafer may prevailingly bemade of, e.g., a semiconductor material, a polymer material, a compositematerial including metals and polymers or polymers and glass materials.In particular, hardenable materials such as thermally or UV-curablepolymers may be used as wafer materials in conjunction with thepresented invention.

“Horizontal”: cf. “Wafer”

“Lateral”: cf. “Wafer”

“Vertical”: cf. “Wafer”

“Light”: Most generally electromagnetic radiation; more particularlyelectromagnetic radiation of the infrared, visible or ultravioletportion of the electromagnetic spectrum.

Optoelectronic modules, such as proximity sensors, are ubiquitous inmyriad high-tech, especially, consumer-oriented products. Suchapplications demand large-scale, cost-effective manufacture ofoptoelectronic modules with both optimal performance and minimizeddimensions. Cost efficiency can be achieved by manufacture of theoptoelectronic modules via wafer-level techniques or othermass-fabrication techniques. However, these techniques often introduce acompromise between minimized dimensions (i.e., footprint and/or height)and optimal performance.

Apertures and their corresponding aperture stops (also simply referredto as stops), for example, are integral to the performance of manyoptoelectronic modules. Their effect on optical systems is wellestablished. Consequently, their precise positioning can be crucial inorder to achieve optimal performance.

This is accomplished, in some cases, by incorporating the aperture stopsinto optoelectronic modules via a separate aperture-stop wafer or bafflewafer (such as a non-transparent flat wafer with through holes).However, the height of such a separate wafer contributes to the heightof the resulting optoelectronic modules.

Alternatively, aperture stops can be applied by coating surfaces ofoptoelectronic components on the wafer level. However, upon separatingthe components, the coated aperture stops can delaminate or crack.

Furthermore, heating the opto-electronic modules to rather hightemperatures, e.g., for improving adhesion of an aperture-stop coatingfor decreasing the risk of cracks and delamination, or for curing ofinvolved materials, can result in additional problems such as insignificant warpage degrading the function of the modules.

It is known to use spacer wafers (or other intermediary components)which vertically separate different wafers such as wafers carryingpassive optical components, e.g., lenses or filters from wafers carryingactive optical components, e.g., light emitters and/or light detectors.Doing so results in relatively small direct contact areas between thewafers. This can be a way to reduce warpage problems, however at theexpense of the spacer wafer contributing to the module thickness.

In an attempt to reduce the thickness of the modules by omitting such aspacer wafer and accepting an increased direct contact area betweenwafers, warpage problems tend to strongly increase. The warpage problemscan be significant when materials with different coefficients of thermalexpansion (CTEs) are used and/or when polymeric materials are used whichtend to shrink considerably upon curing and/or solidifying.

Furthermore, if spacer wafers shall be dispensed with, another functionoften fulfilled by spacer wafers may have to be replaced in some way,namely to optically isolate active optical components of theopto-electronic modules, such as to avoid that light is emitted by anactive optical component of the module along undesired paths and/or toavoid that light can enter the module along undesired path and bedetected by an active optical component of the module; in other words,the function can be to isolate the active optical components fromastray/stray light.

In addition, separate spacer wafers need to have at least some minimumwall width in order to have a required mechanical stability. This cancontribute to an increased footprint of the opto-electronic modules.

The provision of separate wafers for passive optical components such asfor lenses or baffles can also be considered to contribute to anincreased thickness of opto-electronic modules which may be avoidablewhen a very low thickness of opto-electronic modules shall be achieved.

The present disclosure describes optical devices and optical devicewafers which can be ultrathin, as well as their manufacture viamass-fabrication techniques. Various implementations are described thatcan provide one of more of: precisely positioned aperture stops;aperture stops that are not subject to delamination problems; moduleside walls which can be non-transparent (opaque) and can have a minimumfootprint; substrates and substrate wafers which can be ultrathin; lowwarpage.

An example of an advantage of a version of the invention is to createoptical devices, e.g., opto-electronic modules, which are very thin. Onthe one hand, corresponding optical devices themselves shall beprovided, and on the other hand, respective methods for manufacturingthe optical devices shall be provided.

Another example of an advantage of a version of the invention is toprovide optical devices which have a very small footprint.

Another example of an advantage of a version of the invention is to makepossible an accurate positioning of apertures.

Another example of an advantage of a version of the invention is toachieve that no or only very little delamination and/or crackingproblems occur during manufacture and/or during use of the opticaldevices.

Another example of an advantage of a version of the invention is toachieve a good optical isolation of active optical components of theoptical devices from astray/stray light.

Another example of an advantage of a version of the invention is toenable high-yield manufacture of optical devices.

Another example of an advantage of a version of the invention is tocreate optical devices which are—where desired—particularly light-tight.

Further objects and various advantages emerge from the description andembodiments below.

At least one of these advantages is at least partially achieved byapparatuses and methods according to the patent claims.

Several aspects are described in the present patent application, whichcan be taken separately but which can also be combined with each other.

First Aspect

In the method according to the first aspect, optical devices aremanufactured which include at least one active optical component each.Each of the active optical components can be operable to emit or senselight of a particular range of wavelengths.

In instances, the optical device is a dual channel device, such as,e.g., a proximity sensor, including at least one light emitter and atleast one light detector. Said particular range of wavelengths can beidentical for these active optical components.

It is noted that a light emitter and a light detector optionally canemit and sense, respectively, also further light, i.e. also light offurther wavelength ranges in addition to said light of said particularrange of wavelengths.

Said particular range of wavelengths can be, e.g, in the infrared rangeof the electromagnetic spectrum.

An initial wafer is provided which includes the active opticalcomponents and a wafer-size substrate. As an option, the active opticalcomponents are included in the substrate. In an alternative option, theactive optical components are mounted on the substrate.

In a subsequent step, a clear encapsulation is applied to the activeoptical components. Application of the clear encapsulation can includeapplying across the substrate a clear encapsulation material, e.g., aliquid polymeric material, which is translucent to light of theparticular range of wavelengths.

After its application, the clear encapsulation material can be hardened,e.g., cured.

The clear encapsulation can be provided for providing mechanicalprotection for the active optical components. It can furthermore be astructural basis for further constituents of the optical device.

In a subsequent step, an opaque coating material is applied onto asurface of the clear encapsulation. That surface can be, e.g., alignedparallel to the substrate. That surface can be arranged opposite thesubstrate.

The opaque coating material can be a photostructurable material such asa photo resist. By means of photostructuring, structuring can beaccomplished with very high precision, and very thin coatings can beused. This can enable production, e.g., of high-quality apertures to beproduced.

Subsequently, the opaque coating material is structured, e.g.,photolithographically, to produce an opaque coating on the surface ofthe clear encapsulation which is opaque for light of the particularrange of wavelengths. During structuring, the opaque coating materialcan be selectively exposed to radiation such as UV radiation. In asubsequent developing process, portions of the opaque coating material(irradiated portions or not-irradiated portions) can be selectivelyremoved from the clear encapsulation.

The opaque coating defines a multitude of apertures, wherein eachaperture can be associated with one of the active optical components andcan be aligned with respect to the respective associated active opticalcomponent. Referring to corresponding aperture stops, one canalternatively say that the opaque coating includes a multitude of stops,wherein each stop can be associated with one of the active opticalcomponents and aligned with respect to the respective associated activeoptical component.

The above does not exclude that some of the apertures and stops,respectively, are associated with two (or more) active opticalcomponents. And it neither excludes that some of the active opticalcomponents are not associated with one of the apertures and aperturestops, respectively.

In a subsequent step, a wafer-level arrangement of intermediate productsis produced, wherein each intermediate product has side walls andincludes a portion of the clear encapsulation, one of the active opticalcomponents and, if one of the apertures is associated with said activeoptical component, also the respective associated aperture. Producingthe wafer-level arrangement of intermediate products includes producingtrenches extending through the clear encapsulation material andestablishing the side walls.

The trenches can extend through the opaque coating.

The portions of the clear encapsulation can be separate from each other,with no clear encapsulation material of the clear encapsulationinterconnecting them.

The term “wafer-level arrangement” of items (such as of the intermediateproducts) includes that the items are held in fixed relative positions(across the wafer). This can be accomplished, e.g., by the substrate.

In a subsequent step, an opaque encapsulation is applied to theintermediate products, which includes applying to the wafer-levelarrangement of intermediate products an opaque encapsulation material,e.g., a liquid polymeric material, and thereby filling the trenches(with the opaque encapsulation material). By filling the trenches, sidewalls, e.g., all side walls, of the intermediate products, e.g., of allintermediate products, are covered by the opaque encapsulation material.

Subsequently, the opaque encapsulation material is hardened. The opaqueencapsulation material (at least after hardening) is opaque to light ofthe particular range of wavelengths. For accomplishing the hardening,e.g., by curing, a heat treatment, can be applied.

In a subsequent step, singulated optical modules are produced. Thisincludes cutting through the opaque encapsulation material present inthe trenches. The singulated optical modules include one of theintermediate products each, and at least one of the side walls, e.g.,each of said side walls, of each respective intermediate product iscovered by a respective portion of the opaque encapsulation material.

For example, the singulating can be accomplished by cutting through theopaque encapsulation material present in the trenches along singulationlines running between mutually opposing side walls of neighboringintermediate products. The singulation lines can run along and throughthe trenches.

The singulating can include dicing such as dicing by means of lasercutting or by means of a dicing saw.

The optical devices can include passive optical components, e.g., oneper optical device and/or one per channel.

The passive optical components can include, e.g., lenses or lenselements.

Each of the passive optical components can be associated with one of theactive optical components.

Each of the passive optical components can be aligned with respect toone of the apertures.

In instances, the production of the clear encapsulation includes ashaping step, e.g., during or after application of the clearencapsulation material in a liquid state and before hardening the clearencapsulation material. In said shaping step, a shape of the clearencapsulation is determined (in the sense of “is fixed”).

In case the passive optical components are included in the clearencapsulation, also the passive optical components can, in instances, beshaped in said shaping step.

For example, the clear encapsulation can be applied using a replicationtechnique. E.g., a molding process such as vacuum injection molding canbe used for applying the clear encapsulation.

Accordingly, the clear encapsulation can be produced in a replicationprocess, including producing (in the same replication process) thepassive optical components.

For example, the clear encapsulation can be shaped by means of areplication tool such as a mold.

Such a replication tool can include a multitude of shaping sections,each shaping section having a shaping surface being a negative replicaof a surface of one of the passive optical components.

In some embodiments, the method includes, prior to applying the clearencapsulation, applying a resilient encapsulation to the active opticalcomponents. For accomplishing this, a resilient encapsulation materialwhich is resilient and translucent to light of the particular range ofwavelengths can be applied to the active optical components.

In some embodiments, the clear encapsulation has a stepped structureincluding depressions and/or protrusions limited by steps. At steps, apropagation of cracks in the opaque coating can be stopped. This way,the apertures (and the corresponding stops, respectively) can beprotected from damage, e.g., during producing the trenches.

In instances, producing the stepped structure includes removing aportion of the clear encapsulation material from the clearencapsulation, such as by producing grooves in the clear encapsulationmaterial, e.g., after hardening the clear encapsulation material.

In other instances, the clear encapsulation is provided with the steppedstructure during applying the clear encapsulation material. For example,the stepped structure can be produced using a structured replicationtool including a negative replica of the stepped structure for shapingthe clear encapsulation material in a replication process.

In instances, the replication tool is structured for producing thestepped structure and the passive optical components.

In some embodiments, each of the apertures is separated from any of thetrenches by at least one region which is free of the opaque coatingmaterial. This can be the case before producing the trenches. E.g., theat least one region can be produced by the structuring of the opaquecoating material.

The at least one region can protect the apertures from damage, e.g.,from cracks.

Accordingly, the opaque coating can be structured to include the atleast one region free of the opaque coating material, e.g., alreadybefore the trenches are produced.

For example, in one and the same structuring process, such as in one andthe same photolithographic process, the apertures and said regions canbe produced.

In some embodiments, the trenches along trench lines.

The trench lines can define a rectangular grid.

In some embodiments, applying the opaque encapsulation includesexecuting a replication process. In the replication process, areplication tool can be used for shaping the opaque encapsulationmaterial.

The replication process can include, e.g., a vacuum injection moldingprocess.

In some embodiments, applying the opaque encapsulation includesexecuting a replication process using a resilient replication toolincluding at least one resilient inner wall. The resilient inner wallcan be made, e.g., of a silicone, such as of PDMS. The opaqueencapsulation material can be shaped by the resilient inner wall. Theopaque encapsulation material can be shaped by a replication surfaceconstituted by a surface of the resilient inner wall.

Due to the resilience, the replication tool can, to some extent, adjustto possibly existing lacking flatness of the wafer.

In some embodiments, applying the opaque encapsulation includes amolding process using a mold including the resilient inner wall. Themolding process can be a vacuum injection molding process.

In some embodiments, the applying of the opaque encapsulation includes

-   -   shaping the opaque encapsulation material in a replication        process using a replication tool including a surface including a        replication surface for shaping the opaque encapsulation        material; and    -   pressing the replication surface against the opaque coating        while shaping the opaque encapsulation material.

The replication tool can be, e.g., a resilient replication toolincluding at least one resilient inner wall such as described above.

During the pressing, a multitude of hollows can be established, and amultitude of seals can be established. Each of the seals can completelysurround one of the hollows and prevent that any of the opaqueencapsulation material enters the respective surrounded hollow. Each ofthe hollows can enclose one of the apertures. Each of the seals can beformed by a respective section of the opaque coating abutting arespective section of the surface of the replication tool.

Accordingly, contamination or damage of the apertures by the opaqueencapsulation material during its application can be avoided.

The opaque encapsulation can be abutting and/or partially overlappingthe opaque coating. This can contribute to light tightness of theoptical device.

Application of the opaque encapsulation material can be restricted tolocations which are distant from any of the apertures. This is a way ofensuring that the apertures are defined by the opaque coating only, butnot by the opaque encapsulation. This can make possible the productionof higher precision apertures (and corresponding stops), e.g., in case athickness of the opaque coating is lower, e.g., lower by a factor ofthree or more, than a thickness of the opaque encapsulation. Thesethicknesses can be determined along a vertical direction, i.e.perpendicularly to the substrate.

In some embodiments, the method includes producing cuts in the opaqueencapsulation material. Producing the cuts can preserve the substrate,the opaque encapsulation and the arrangement of intermediate productsunsegmented. The clear encapsulation can remain uncut despite the cutsin the opaque encapsulation material. The cuts can be produced afterhardening the opaque encapsulation and before producing the singulatedoptical modules.

The cuts can, in instances, relax mechanical stress present in thewafer.

The cuts can, in instances, reduce an aggregation of mechanical stressin the wafer arising from subsequent steps such as subsequent heattreatments.

In instances, the cuts can be produced after prior execution of a heattreatment in which the opaque encapsulation material is hardened, e.g.,cured.

In instances, after producing the cuts, a heat treatment is applied tothe wafer, e.g., a heat treatment for improving adherence of the opaquecoating to the clear encapsulation and/or a heat treatment carried outbefore the singulation. This heat treatment can be carried out, e.g.,after the wafer has been removed from a replication tool for shaping theopaque encapsulation material (cf. above).

In some embodiments, the hardening of the opaque encapsulation materialincludes application of a first heat treatment, and the cuts in theopaque encapsulation material are produced after the first heattreatment; and after producing the cuts and before the singulation, asecond heat treatment is applied.

The cuts can run along cut lines. And they can extend only partiallyinto the opaque encapsulation. And the cuts can extend not at all intothe clear encapsulation.

The cuts can be produced without thereby segmenting the opaqueencapsulation or any of the intermediate products into segments.

In instances, the method includes after applying the opaqueencapsulation and before producing the singulated optical modules—and ifthe cuts are produced: before producing the cuts—the step of applying aheat treatment.

This heat treatment can be applied for strengthening an adhesion betweenthe opaque coating and the clear encapsulation.

In some embodiments, the method includes applying a spectral filterlayer onto the singulated optical modules.

The spectral filter layer can be applied after producing the singulatedoptical modules. The filter can let pass, e.g., IR light.

The application of the spectral filter layer can include a hardeningstep, such as an irradiation with light, e.g., with UV light.

In some embodiments, the spectral filter layer covers the apertures.

In some embodiments, the cuts in the opaque encapsulation material areat least partially filled by material of the spectral filter layer. Inalternative embodiments, however, the cuts in the opaque encapsulationmaterial are free from material of the spectral filter layer.

Mechanical stress due to application of the spectral filter layer, e.g.,stress from shrinkage during curing, and its detrimental effects such ascrack formation and delamination can be reduced when singulation takesplace prior to application of the spectral filter layer.

In some embodiments, the method includes, after the producing of thesingulated optical modules, an application of a heat treatment. In sucha heat treatment, the singulated optical modules can be thermallystabilized. The heat treatment can be carried out, if provided, afterapplication of the spectral filter layer (cf. above).

In another variant (“other variant”) of the invention, a spectral filterlayer is applied in a way different from the way described above. Inthis “other variant”, the spectral filter layer is produced on a surfaceof the clear encapsulation (and thus much earlier in the process). Infact, in this “other variant”, the described opaque coating can bedispensed with. And moreover, some functions fulfilled by the opaquecoating can be fulfilled by the spectral filter layer. E.g., theapertures can be defined by the spectral filter layer together with theopaque coating.

This can be accomplished by having the spectral filter layer materialoccupy the (lateral) areas where the apertures shall be located, and byapplying the opaque encapsulation material, aperture stops mating thespectral filter material (and thus, mating the apertures) are produced.

By ensuring that the (lateral) areas occupied by the spectral filterlayer material (and thus the (lateral) areas where the apertures shallbe located) remain uncovered by the opaque encapsulation, high precisionapertures can be produced. E.g., the spectral filter material can bephotostructurable, such that shape and position of the apertures aredetermined by a photostructuring technique. Precision requirements forthe application of the opaque encapsulation can then be relativelyrelaxed. The opaque encapsulation can be applied, e.g., by means of areplication technique, such as by molding.

An optical device according to the “other variant” can include one ormore apertures, wherein each of the apertures is delimited by the opaqueencapsulation material (thus forming the corresponding aperture stop)and each of the apertures is filled by the spectral filter layermaterial.

In the “other variant”, the method according to the first aspect can bedescribed as a method for manufacturing optical devices including anactive optical component each, the active optical components beingoptical components for emitting or sensing light of a particular rangeof wavelengths, wherein the method includes:

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths;    -   applying onto a surface of the clear encapsulation a spectral        filter layer material;    -   producing a spectral filter layer on the surface of the clear        encapsulation, wherein the producing the spectral filter layer        includes structuring the spectral filter layer material;    -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;    -   applying an opaque encapsulation to the intermediate products,        including applying to the wafer-level arrangement of        intermediate products an opaque encapsulation material, thereby        filling the trenches, and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths;    -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

The spectral filter layer can be translucent for light of the particularrange of wavelengths and be opaque for light of another range ofwavelengths. For example, each of the optical devices can include alight emitter (i.e. an optical component for emitting light) and a lightdetector (i.e. an optical component for sensing light), and the lightwavelengths emittable from the light emitter being detectable by thelight detector, but the light detector being sensitive to light offurther wavelengths not emittable from the light emitter. In this case,the spectral filter layer can be, e.g., translucent for light of saidwavelengths emittable from the light emitter and opaque for light ofsaid further wavelengths.

The spectral filter layer can let pass, e.g., IR light.

Applying the spectral filter layer material can be accomplished by,e.g., a spray coating process or a spinning process. For example, incase the clear encapsulation includes passive optical components, thespectral filter layer material can be applied in a spray coatingprocess. In another example, the clear encapsulation includes no passiveoptical components and/or the surface of the clear encapsulation isplanar, and the spectral filter layer material can be applied onto thesurface in a spin coating process.

Producing the spectral filter layer can include a hardening step, suchas an irradiation with light, e.g., with UV light.

Optical devices that can be manufactured by one of the describedmanufacturing methods can include the described singulated opticalmodules. They can, e.g., be identical therewith.

In the following, we disclose optical devices by describing theirrespective possible structural features. Of course, the optical devicescan inherit features possibly not explicitly mentioned below, butarising from and/or described in conjunction with the manufacturingmethods.

The optical device can include

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths.

The one or more active optical components can be attached to thesubstrate member.

The clear encapsulation material can establish an overmold for the oneor more active optical components.

The clear encapsulation material can establish an overmold for at leasta portion of the substrate member.

The one or more active optical components can be encapsulated by theclear encapsulation material.

The opaque coating material can be a material which is different fromthe opaque encapsulation material.

The opaque coating material can be photostructurable.

The substrate member can be plate-shaped.

The substrate member can have a first and a second member surfaces whichare mutually parallel and opposing.

Most of the clear encapsulation material can be surrounded by the opaqueencapsulation material.

The opaque coating material can be present on and interfacing the clearencapsulation material.

The opaque coating material can be present on a surface of the clearencapsulation material, wherein said surface can be opposing anothersurface of the clear encapsulation material facing the substrate member.

The wall structure can include one or more vertically aligned walls.

The opaque wall structure can interface the substrate member, the clearencapsulation material and the opaque coating material.

In some embodiments, the optical device includes one or more passiveoptical components made of the clear encapsulation material.

In some embodiments, a thickness of the substrate member in a firstregion in which the opaque wall structure abuts the substrate member issmaller than a thickness of the substrate member in a second regionencircled by the first region. E.g., the one or more active opticalcomponents can, in the second region, be attached to the substratemember.

In some embodiments, the optical device includes a resilientencapsulation material establishing an overmold for the one or moreactive optical components, wherein the clear encapsulation materialestablishes an overmold for the resilient encapsulation material. Insuch embodiments, the clear encapsulation material can still establishan overmold for the one or more active optical components. It can, atthe same time, establish an overmold for the resilient encapsulationmaterial.

In some embodiments, the clear encapsulation has a stepped structureincluding one or more steps. The opaque coating can extend across theone or more steps. The opaque coating can have a stepped structure, too.

In some embodiments, the opaque wall structure includes at least onewall exhibiting an L-shape in a cross-section. The L-shape can berelated to the stepped structure described above. The cross-section canbe running through the substrate member, the clear encapsulationmaterial, the opaque coating material and the opaque wall structure. Thecross-section can run through at least one of the one or more passiveoptical components, too. The cross-section can be a verticalcross-section.

In some embodiments, the substrate member is opaque for light of theparticular range of wavelengths, and the one or more active opticalcomponents are, with the exception of the at least one aperture,light-tightly enclosed for light of the particular range of wavelengthsby the substrate member, the opaque wall structure and the opaquecoating material. When the one or more active optical components are(with the exception of the at least one aperture) completely opaquelycovered for light of the particular range of wavelengths by thesubstrate member, the opaque wall structure and the opaque coatingmaterial, undesired light paths can be suppressed.

In some embodiments, the optical device is devoid any hollow inclusions.The term hollow inclusion is meant to say that the inclusion contains avacuum or a gas or a liquid and is completely surrounded by solidmaterial (of the optical device). Several prior art optical deviceswhich are produced by stacking wafers include large hollow inclusions,e.g., in a space between a section of the lens wafer, a section of thespacer wafer and a section of the substrate wafer.

In some embodiments, the optical device is a dual-channel device, e.g.,a proximity sensor. The dual-channel device can include (as the activeoptical components) at least one light emitter and at least one lightsensor. And the opaque wall structure can include walls contributing toan outer housing of the optical device and, in addition, walls which areinner walls of the dual-channel device can optically separate thechannels from each other.

The optical device according to the “other variant” include one or moreapertures covered by the spectral filter layer material and need notinclude, in particular do not include, an opaque coating and associatedopaque coating material.

E.g., the optical device (according to the “other variant”) can include

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   a spectral filter layer material;    -   an opaque encapsulation material opaque to light of the        particular range of wavelengths establishing an opaque wall        structure;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the clear encapsulation materialestablishes an overmold for the one or more active optical componentsand has a face on which the spectral filter layer material is present.

In one embodiment, the opaque encapsulation material establishes one ormore aperture stops associated with the one or more active opticalcomponents each, the one or more aperture stops delimiting an apertureeach, wherein the apertures are covered by the spectral filter layermaterial.

Any of the aspects described in the following can be combined with thefirst aspect described above including the “other variant”, as far aslogically possible. E.g., the following aspects can be implemented asspecific embodiments of the first aspect, possibly also in the “othervariant”. However, they can also be implemented separate therefrom. And,as indicated, the various aspects can also be combined with each other,pairwise, or combining three or more of them.

Second Aspect

This aspect relates to a resilient encapsulation, e.g., to the resilientencapsulation described above already and/or to the resilientencapsulation described elsewhere herein.

The method according to the second aspect is a method for manufacturingoptical devices including an active optical component each, the activeoptical components being optical components for emitting or sensinglight of a particular range of wavelengths, wherein the method includes:

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a resilient encapsulation to the active optical        components by applying to the active optical components a        resilient encapsulation material which is resilient and        translucent to light of the particular range of wavelengths.

The resilient encapsulation can reduce stress to which the activeoptical components are exposed, e.g., during further manufacturingsteps.

Not only the active optical components themselves, but also electricalconnections between the active optical components and the substrate can,in instances, be coated by the resilient encapsulation material. Suchelectrical connections can be, e.g., wire bonds or solder balls.

Being compliant, the resilient encapsulation can absorb, at least inpart, forces otherwise acting on the active optical components and/or onelectrical connections between the active optical components and thesubstrate.

E.g., the resilient encapsulation material can be applied across thesubstrate. Thus, a wafer-size resilient encapsulation can be produced.It is, however, also possible to apply the resilient encapsulationmaterial only locally to the active optical components.

In some embodiments, the resilient encapsulation material is a silicone,e.g., PDMS.

In some embodiments, the resilient encapsulation material is applied bythe aid of a spray coating process.

In some embodiments, the applied resilient encapsulation material ishardened, e.g., cured. This can be accomplished, e.g., by means ofirradiation with light such as with UV light. Alternatively or inaddition, heat can be applied for accomplishing the hardening.

In some embodiments, the resilient encapsulation material is applied intwo or more consecutive spray coating steps.

In some embodiments, the applied resilient encapsulation material ishardened after one or more of such consecutive spray coating steps inaddition to a final hardening step at the end of the application of theapplication of the resilient encapsulation.

In some embodiments, the method includes, after the application of theresilient encapsulation

-   -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths.

The clear encapsulation can provide mechanical protection for the activeoptical components. Furthermore, as described above, passive opticalcomponents can be established by the clear encapsulation.

With the resilient encapsulation present, in some embodiments, the clearencapsulation is devoid any direct contact with the substrate. Theresilient encapsulation can be separating the clear encapsulation fromthe wafer-size substrate. In other cases, where the clear encapsulationmaterial is merely locally present, regions exist where the clearencapsulation is in direct contact with the substrate and other regionsexist where the clear encapsulation is separated from the wafer-sizesubstrate by the resilient encapsulation.

An optical device according to the second aspect includes

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a resilient encapsulation material translucent to light of the        particular range of wavelengths;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the resilient encapsulation materialestablishes an overmold for the one or more active optical components.

In some embodiments, the optical device includes, in addition,

-   -   a clear encapsulation material translucent to light of the        particular range of wavelengths.

In some embodiments, the clear encapsulation material and the resilientencapsulation material together establish an overmold for the one ormore active optical components.

In some embodiments, the clear encapsulation material is separated fromthe substrate member by the resilient encapsulation material, at leastin a region in which the one or more active optical components arepresent.

Third Aspect

This aspect relates to a coating present on a specifically structuredencapsulation, e.g., to the opaque coating described above alreadyand/or to the opaque coating described elsewhere herein, present on theclear encapsulation described above already and/or to the clearencapsulation described elsewhere herein. The encapsulation can bestructured to exhibit the described above and/or below described steppedstructure.

The method according to the third aspect is a method for manufacturingoptical devices, wherein the method includes:

-   -   providing a wafer including a wafer-size substrate on which an        encapsulation is present, e.g., on which a clear encapsulation        is present which is translucent to light of a particular range        of wavelengths;    -   applying onto the surface of the encapsulation a coating        material, e.g., an opaque coating material;    -   producing a coating made of the coating material on the surface        of the clear encapsulation, e.g., an opaque coating which is        opaque for light of the particular range of wavelengths;

wherein the encapsulation has a surface at which it has a steppedstructure including depressions and/or protrusions limited by steps.

This can stop crack propagation in the coating at the steps. This canprotect portions of the coating from delamination, e.g., protectspecific structured portions such as portions in which apertures areformed.

The depressions can be grooves.

In some embodiments, the coating has a stepped structure, too. Thatstepped structure can be a reproduction of the stepped structure of theencapsulation, wherein the reproduction not necessarily needs to be anidentical reproduction. E.g., step heights can be different, e.g., by upto a factor of 1.5, and positions of steps can be different, e.g., bedisplaced by e.g., up to 5 times a thickness of the coating.

In some embodiments, the stepped structure of the coating emerges fromapplying the coating material onto the surface of the encapsulationmaterial.

In some embodiments, the encapsulation establishes passive opticalcomponents, e.g., lenses.

In some embodiments, the surface is a surface facing away from thesubstrate.

In some embodiments, the coating material is photostructurable.

In some embodiments, the coating has a thickness of between 1 μm and 10μm.

In some embodiments, producing the (optionally opaque) coating includesstructuring the (optionally opaque) coating material.

In some embodiments, producing the (optionally opaque) coating includeshardening the (optionally opaque) coating material.

In some embodiments, the coating defines a multitude of apertures.

In some embodiments, the optical devices include an active opticalcomponent each, the active optical components being optical componentsfor emitting or sensing light of the particular range of wavelengths.

In some embodiments, the coating defines a multitude of apertures, eachaperture being associated with one of the active optical components andaligned with respect to the respective associated active opticalcomponent.

In some embodiments, when the encapsulation includes a multitude ofpassive optical components (such as lenses), the coating defines amultitude of apertures, each aperture being associated with one of thepassive optical components and aligned with respect to the respectiveassociated passive optical component.

In some embodiments, the method includes

-   -   applying a the (optionally clear) encapsulation to the active        optical components;

wherein the applying the encapsulation includes applying across thesubstrate an encapsulation material, e.g., applying across the substratea clear encapsulation material which is translucent to light of theparticular range of wavelengths.

In some embodiments, the method includes producing the stepped structurein a replication process, e.g., in a molding process such as in a vacuuminjection molding process. E.g., a structured replication tool can beused for shaping the encapsulation material so as to exhibit the steppedstructure. Alternatively, the method can include producing the steppedstructure by removing a portion of the clear encapsulation material.This can be accomplished, e.g., by means of a dicing saw.

In some embodiments, the coating defines a multitude of apertures, andeach of the apertures is surrounded by at least one step of the steppedstructure.

In some embodiments, the method includes, subsequently to producing thecoating,

-   -   producing trenches extending through the (optionally opaque)        coating and extending into or through the (optionally clear)        encapsulation material.

In some embodiments, the method includes, subsequently to producing thecoating,

-   -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the (optionally clear) encapsulation (and—if        present—one of the active optical components);

wherein producing the wafer-level arrangement of intermediate productsincludes producing trenches, wherein the trenches extend through the(optionally clear) encapsulation material and through the (optionallyopaque) coating and establish the side walls.

Producing trenches can produce considerable stress in the coating whichcan lead to delamination problems in the coating. Propagation ofcorresponding cracks in the coating can be stopped at the steps of thestepped structure.

There can be areas in which the coating is structured, e.g., to formapertures such as the apertures already described or described below,and by means of the steps of the stepped structure, such areas can beprotected, e.g., by providing that steps of the stepped structure arepresent between each of the trenches and each of the areas. E.g., eachof the areas can be separated from any of the trenches by at least oneregion which is free of the opaque coating material.

For example, each of the apertures can be separated from any of thetrenches by at least one region which is free of the (optionally opaque)coating material.

In some embodiments, in which the coating establishes apertures and inwhich trenches are produced, the steps of the stepped structure runalong step lines, and between each of the apertures and any of thetrenches, one of the step lines is present.

In some embodiments, the method includes producing the steppedstructure, and the producing the stepped structure includes producinggrooves in the clear encapsulation material. Those grooves can run alongthe step lines.

In some embodiments, the trenches and the grooves are aligned parallelto each other.

In some embodiments, a thickness of the coating is less than a stepheight of steps of the stepped structure, e.g., the thickness amounts toless than two times the step height.

An optical device according to the third aspect includes

-   -   an encapsulation material, e.g., a clear encapsulation material        translucent to light of a particular range of wavelengths;    -   a coating material, e.g., an opaque coating material opaque for        light of the particular range of wavelengths;

wherein the encapsulation material has a face on which the coatingmaterial is present, and wherein the encapsulation material has astepped structure at said face.

In some embodiments, also the coating has a stepped structure, e.g.,replicating the stepped structure at the face of the encapsulationmaterial.

In some embodiments, the stepped structure includes at least onedepression and/or at least one protrusion limited by at least one step.

In some embodiments, the optical device includes a side wall structuresuch as, e.g., side walls laterally surrounding the encapsulationmaterial. In this case, steps of the stepped structure can be surroundedby the side wall structure. E.g., any step of the stepped structure canbe laterally surrounded by side walls of the side wall structure.

In some embodiments, the coating establishes at least one aperture, andthe at least one aperture is laterally separated from the wall structureby steps of the stepped structure.

In some embodiments, the optical device includes a substrate member onwhich the encapsulation material is present. (This does not exclude thata resilient encapsulation material is located in between, cf., e.g., thesecond aspect above.)

In some embodiments, the optical device includes

-   -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths.

They can be encapsulated in the (optionally clear) encapsulationmaterial.

Fourth Aspect

This aspect relates to trenches, such as, e.g., the already describedtrenches and/or the trenches described elsewhere herein, which can befilled with an opaque encapsulation material, such as the alreadydescribed opaque encapsulation material and/or the opaque encapsulationmaterial described elsewhere herein, e.g., so as to make possible toproduce optical modules having sides walls made of opaque encapsulationmaterial.

The method according to the fourth aspect is a method for manufacturingoptical devices including an active optical component each, the activeoptical components being optical components for emitting or sensinglight of a particular range of wavelengths, wherein the method includes:

-   -   providing a wafer including a wafer-size substrate on which a        clear encapsulation is present which is translucent to light of        the particular range of wavelengths;    -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;    -   applying an opaque encapsulation to the intermediate products,        including applying to the wafer-level arrangement of        intermediate products an opaque encapsulation material, thereby        filling the trenches, and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths.

This can make possible to produce optical devices which have a desireddegree of light tightness.

The trenches can be produced, e.g., by dicing with a dicing saw.

In some embodiments, the trenches extend into, but not through thesubstrate. This can contribute to reproducibly achieve a high lighttightness, e.g., in regions where the trenches are close to or extendinto, respectively, the substrate.

If the resilient encapsulation described herein above and below ispresent, the trenches can extend through the corresponding resilientencapsulation material, too.

In some embodiments, the method includes

-   -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

In some embodiments, the method includes

-   -   applying the clear encapsulation to the active optical        components, wherein the applying the clear encapsulation        includes applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths.

In some embodiments, the method includes

-   -   applying onto a surface of the clear encapsulation an opaque        coating material which is photostructurable; and    -   producing an opaque coating on the surface of the clear        encapsulation which is opaque for light of the particular range        of wavelengths, wherein the producing the opaque coating        includes structuring the opaque coating material.

Therein, the opaque coating can define a multitude of apertures, eachaperture being associated with one of the active optical components andaligned with respect to the respective associated active opticalcomponent.

Optical devices can be produced this way, which are light-tight (withrespect to light of the particular range of wavelengths) except for theone or more apertures defined by the opaque coating material of theoptical device.

The producing of the opaque coating can be accomplished before theapplication of the opaque encapsulation. A possible consequence thereofcan be that processes which can be related to the producing of theopaque coating, e.g. processes applied during photostructuring theopaque coating material, such as a spinning process (for applying theopaque coating material) and/or an (optionally wet-chemical) developmentprocess, are in that case applied while the clear encapsulation materialis still a wafer-size item and not a wafer-level arrangement ofintermediate products. This can enhance manufacturability and/orachievable precision. E.g., depending on processes applied, some of theintermediate products could possibly leave their position because of theapplied processes and/or relative positions of intermediate productscould possibly change because of the applied processes.

A width of the trenches can be between 50 μm and 1000 μm or, ininstances, between 100 μm and 800 μm. Such widths can be suitable forproducing, on the one hand, optical devices of small lateral dimensionand, on the other hand, to reproducibly produce the trenches and fillthem with the opaque encapsulation material.

In some embodiments, the application of the opaque encapsulationmaterial is accomplished using a replication technique such as a moldingprocess, e.g., a vacuum injection molding process.

An optical device according to the fourth aspect includes

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the clear encapsulation materialestablishes an overmold for the one or more active optical components,wherein the opaque wall structure is abutting side walls of the clearencapsulation material.

The opaque wall structure can laterally surround the clear encapsulationmaterial.

The device can furthermore include

-   -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components.

In some embodiments, a thickness of the substrate member in a firstregion in which the opaque wall structure abuts the substrate member issmaller than a thickness of the substrate member in a second regionencircled by the first region. This can contribute to an enhancedlight-tightness of the optical device.

In some embodiments, a vertical extension of the opaque coating materialcan overlap with a vertical extension of the opaque encapsulationmaterial of the opaque wall structure. In instances, a verticalextension of the opaque coating material can be included in a verticalextension of the opaque encapsulation material of the opaque wallstructure.

In some embodiments, a vertical extension of the opaque coating materialcan (e.g., in a direction pointing away from the substrate member)terminate together with a vertical extension of the opaque encapsulationmaterial of the opaque wall structure.

In some embodiments, the opaque wall structure includes at least onewall exhibiting an L-shape in a cross-section. This can be the case,e.g., when the clear encapsulation material exhibits a steppedstructure, e.g., when the fourth aspect is combined with the thirdaspect (cf. above).

In some embodiments, the opaque wall structure includes at least onewall exhibiting (at least substantially) a T-shape in a cross-section.This can be the case, e.g., when the clear encapsulation materialexhibits a stepped structure, e.g., when the fourth aspect is combinedwith the third aspect (cf. above). Furthermore, this can be the case ifthe optical device includes at least two intermediate products and/or isa multi-channel device (thus having at least two channels).

Fifth Aspect

This aspect relates to ways of reducing stress in wafer-levelmanufacturing and to corresponding wafer-level manufactured devices.This can find application, e.g., in other methods described herein suchas the described methods for manufacturing optical devices. And thewafer-level manufactured devices can be, e.g., the optical devicesdescribed herein.

This aspect can, e.g., relate to producing cuts in the opaqueencapsulation such as described above or elsewhere in the present patentapplication.

The method according to the fifth aspect can be a method formanufacturing optical devices including an active optical componenteach, the active optical components being optical components foremitting or sensing light of a particular range of wavelengths, whereinthe method includes:

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths;    -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;    -   applying an opaque encapsulation to the intermediate products,        including applying to the wafer-level arrangement of        intermediate products an opaque encapsulation material, thereby        filling the trenches, and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths;    -   producing cuts in the opaque encapsulation while preserving the        clear encapsulation and the arrangement of intermediate products        uncut by the cut and in particular unsegmented;    -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

Producing the cuts can preserve also the opaque encapsulationunsegmented.

Producing the cuts can be accomplished after the applying of the opaqueencapsulation material, before the producing of the singulated modules.It can be accomplished, e.g., after the applying the opaqueencapsulation.

In instances, after producing the cuts, a heat treatment is applied tothe wafer, e.g., a heat treatment carried out before producing the cuts.This heat treatment can be carried out, e.g., after the wafer has beenremoved from a replication tool for shaping the opaque encapsulationmaterial (cf. above).

The cuts can run along cut lines.

In some embodiments, the cuts extend only partially into the opaqueencapsulation material present in the trenches.

In some embodiments, the cuts are laterally positioned within lateralpositions of the trenches.

In some embodiments, the method includes

-   -   applying onto a surface of the clear encapsulation an opaque        coating material, wherein the opaque coating material can be        photostructurable; and    -   producing an opaque coating on the surface of the clear        encapsulation which is opaque for light of the particular range        of wavelengths and which defines a multitude of apertures, each        aperture being associated with one of the active optical        components and aligned with respect to the respective associated        active optical component, wherein the producing the opaque        coating includes structuring the opaque coating material.

These steps can be accomplished, e.g., after applying the clearencapsulation and prior to the producing the wafer-level arrangement ofintermediate products.

A device according to the fifth aspect, which can, e.g., be an opticaldevice, includes

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the clear encapsulation materialestablishes an overmold for the one or more active optical components,and wherein at least one cut it present which extends into the opaquewall structure.

In some embodiments, the at least one cut extends only partially into(and thus not through) the opaque encapsulation material of the opaquewall structure.

In some embodiments, the at least one cut does not extend into the clearencapsulation material. In other words, the at least one cut is locatedat a distance to the clear encapsulation material.

In some embodiments, the at least one cut is located at an outside edgeof the device.

The device can furthermore include

-   -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components.

Sixth Aspect

This aspect relates to an application of a spectral filter layer, e.g.,to the spectral filter layer described above already and/or to thespectral filter layer described elsewhere herein. More specifically, thesixth aspect relates to the “other variant” of the invention alreadyintroduced above, in which the spectral filter layer material is appliedonto the surface of the clear encapsulation before the opaqueencapsulation is applied (and, possibly, also before the wafer-levelarrangement of intermediate products is produced).

In the sixth aspect, the method is a method for manufacturing opticaldevices including an active optical component each, the active opticalcomponents being optical components for emitting or sensing light of aparticular range of wavelengths, and the method includes:

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths;    -   applying onto a surface of the clear encapsulation a spectral        filter layer material;    -   producing a spectral filter layer on the surface of the clear        encapsulation, wherein the producing the spectral filter layer        includes structuring the spectral filter layer material;    -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;    -   applying an opaque encapsulation to the intermediate products,        including applying to the wafer-level arrangement of        intermediate products an opaque encapsulation material, thereby        filling the trenches, and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths;

In particular, the spectral filter layer can define a multitude ofapertures, each aperture being associated with one of the active opticalcomponents and aligned with respect to the respective associated activeoptical component, and the encapsulation material can establish amultitude of aperture stops mating the apertures defined by the spectralfilter layer.

The method can in addition include

-   -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

Structuring the spectral filter layer material can, e.g., beaccomplished photolithographically.

By structuring the spectral filter layer material, patches of thespectral filter layer material can be produced. Those patches can definethe apertures.

In some embodiments, the applying the spectral filter layer includes ahardening step, such as, e.g., irradiation with light such as with UVlight, and/or applying a heat treatment.

The spectral filter layer can remain unchanged by the producing of thetrenches.

In instances, the trenches are only present in locations which are freefrom overlap with the spectral filter layer.

This can prevent delamination of the spectral filter layer materialcaused by producing the trenches.

The spectral filter layer can be translucent for light of the particularrange of wavelengths.

The spectral filter layer can be opaque for light of a range ofwavelengths outside the particular range of wavelengths.

In some embodiments, the spectral filter layer constitutes an IR filter.

As will be appreciated, the sixth aspect can inherit various featuresand steps from other methods herein described. However, when the opaquecoating is dispensed with, features and steps concerning the opaquecoating cannot be applied or have to be replaced by analogous featuresand steps not relating to the opaque coating.

Seventh Aspect

This aspect relates to details of shaping an opaque encapsulationmaterial, e.g., to the opaque encapsulation material described abovealready and/or to the opaque encapsulation material described elsewhereherein.

The method according to the seventh aspect is a method for manufacturingoptical devices including an active optical component each, the activeoptical components being optical components for emitting or sensinglight of a particular range of wavelengths, wherein the method includes:

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths;    -   applying onto a surface of the clear encapsulation an opaque        coating material which can be, e.g., photostructurable;    -   producing an opaque coating on the surface of the clear        encapsulation which is opaque for light of the particular range        of wavelengths and which defines a multitude of apertures, each        aperture being associated with one of the active optical        components and aligned with respect to the respective associated        active optical component, wherein the producing the opaque        coating includes structuring the opaque coating material;    -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;    -   applying an opaque encapsulation to the intermediate products,        including applying to the wafer-level arrangement of        intermediate products an opaque encapsulation material, thereby        filling the trenches, and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths;

wherein applying of the opaque encapsulation includes

-   -   shaping the opaque encapsulation material in a replication        process using a replication tool including a surface including a        replication surface for shaping the opaque encapsulation        material; and    -   pressing the replication surface against the opaque coating        while shaping the opaque encapsulation material.

And during the pressing, a multitude of hollows is established and amultitude of seals is established, each of the seals completelysurrounding one of the hollows and preventing that any of the opaqueencapsulation material enters the respective surrounded hollow. And eachof the hollows encloses one of the apertures, and each of the seals isformed by a respective section of the opaque coating abutting arespective section of the surface of the replication tool.

Accordingly, during shaping the opaque encapsulation material, theopaque encapsulation interacts with the replication tool (and moreprecisely with sections of the surface of the replication tool) in orderto prevent a penetration of the opaque encapsulation material intocertain regions, namely into the hollows formed.

Contamination or damage of the apertures by the opaque encapsulationmaterial can be avoided.

Use of a flat (unstructured) surface of the replication tool can be madepossible this way. And precise lateral adjustment of the replicationtool for accomplishing the shaping of the opaque encapsulation materialcan, in instances, be dispensed with when using a replication tool whosesurface includes the replication surface is a flat (unstructured)surface.

In some embodiments, the surface of the replication tool including thereplication surface is flat (unstructured).

In instances, the replication tool is a resilient replication toolincluding at least one resilient inner wall. E.g., the resilient innerwall can include the surface of the replication tool including thereplication surface.

The shaping of the opaque encapsulation material can include a vacuuminjection molding process.

In some embodiments, passive optical components (such as, e.g., lenses)established by the clear encapsulation contribute to delimiting thehollows.

In some embodiments, the method includes

-   -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

In some embodiments, each of the hollows is confined by

-   -   a portion of the clear encapsulation material, wherein the        portion can, in instances, include a passive optical component        formed by the clear encapsulation material;    -   a portion of the opaque coating; and    -   a portion of the replication surface.

And in instances, each of the hollows is confined by no more than thesethree items.

The device according to the seventh aspect is an optical deviceincluding

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the clear encapsulation materialestablishes an overmold for the one or more active optical components,and wherein a face of the opaque coating material facing away from theclear encapsulation material is arranged in a first plane which isaligned parallel to a lateral plane (horizontal plane) defined by thesubstrate member, and wherein the opaque wall structure has a furtherface which is arranged in the first plane, too.

The further face can be facing away from the substrate member.

The face of the opaque coating can be adjoining the further face of theopaque encapsulation material.

It can contribute to the mechanical stability of the optical device whenthe opaque encapsulation material of the opaque wall structure and theopaque coating both extend to a common plane. E.g., the opaque wallstructure can provide a sideways mechanical protection for the opaquecoating.

Eighth Aspect

This aspect relates to optical devices including two different opaquematerials, one of them defining an aperture, wherein the opaquematerials are abutting and/or overlapping, and to ways of manufacturingthe optical devices. The optical device can be, e.g., the opticaldevices described above already and/or the optical devices describedelsewhere herein. And the two different opaque materials can be, e.g.,the opaque coating material and the opaque encapsulation materiallydescribed above already and/or described elsewhere herein.

The method according to the eighth aspect is a method for manufacturingoptical devices including an active optical component each, the activeoptical components being optical components for emitting or sensinglight of a particular range of wavelengths, wherein the method includes:

-   -   applying an opaque coating material, wherein the opaque coating        can be, e.g., photostructurable;    -   producing an opaque coating which is opaque for light of the        particular range of wavelengths and which defines a multitude of        apertures, each aperture being associated with one of the active        optical components and aligned with respect to the respective        associated active optical component, wherein the producing the        opaque coating includes structuring the opaque coating material;    -   applying an opaque encapsulation, including applying an opaque        encapsulation material and hardening the opaque encapsulation        material, the opaque encapsulation material being opaque to        light of the particular range of wavelengths;

wherein the opaque encapsulation material is applied to abut the opaquecoating.

The opaque coating material can make possible to reproducibly achievehigh-precision apertures having a high-precision alignment. Selecting aphotostructurable opaque coating material can contribute thereto andselecting a low thickness of the opaque coating can contribute thereto,too.

The opaque encapsulation which, e.g., can be a hardenable polymermaterial, e.g., a curable epoxy, can provide mechanical stability of theoptical device. It can establish an opaque wall structure which, e.g.,can establish side walls of the optical device.

In instances, the opaque encapsulation is applied after producing theopaque coating.

In instances, the opaque coating has a multitude of regions including atleast one of the apertures each, and the opaque encapsulation is appliedonly outside said regions.

The opaque encapsulation and the opaque coating can overlap each other,which can contribute to an enhanced light tightness of the opticaldevice (at least as far as the particular range of wavelengths isconcerned). E.g., if the opaque coating is produced on a surface of aclear encapsulation material, and the clear encapsulation material isapplied across a wafer-size substrate, e.g., across a substrate includedin an initial wafer (the initial wafer including the substrate and theactive optical components), the following can apply: Laterally definedregions exist in which a sequence of materials along a verticaldirection pointing away from the substrate is: clear encapsulationmaterial/opaque coating material/opaque encapsulation material.Furthermore, the achievable light tightness can be particularly enduringin the sense that it can continue to exist still after exposure ofrespective optical devices to thermal and/or mechanical stress.

In some embodiments, the method includes

-   -   providing an initial wafer including the active optical        components and a wafer-size substrate;    -   applying a clear encapsulation to the active optical components        including applying across the substrate a clear encapsulation        material which is translucent to light of the particular range        of wavelengths;

wherein the opaque coating material is applied onto a surface of theclear encapsulation, and wherein the opaque coating is produced on thesurface of the clear encapsulation.

In some embodiments, the method includes

-   -   producing a wafer-level arrangement of intermediate products,        each intermediate product having side walls and including a        portion of the clear encapsulation and one of the active optical        components, the producing the wafer-level arrangement of        intermediate products including producing trenches, wherein the        trenches extend through the clear encapsulation material and        establish the side walls;

wherein the opaque encapsulation is applied to the intermediateproducts, and wherein the opaque encapsulation material is applied tothe wafer-level arrangement of intermediate products and thereby fillsthe trenches.

In some embodiments, the method includes

-   -   producing singulated optical modules, including cutting through        the opaque encapsulation material present in the trenches, the        singulated optical modules including one of the intermediate        products each, at least one side wall of each respective        intermediate product being covered by a respective portion of        the opaque encapsulation material.

In some embodiments, the opaque encapsulation material is applied in avacuum injection molding process.

In some embodiments, the opaque coating material is applied by spraycoating.

In some embodiments, the opaque coating material isphotolithographically structured.

An optical device according to the eighth aspect includes

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths;

wherein the one or more active optical components are attached to thesubstrate member, and wherein the opaque coating material and the opaqueencapsulation material are overlapping.

In some embodiments, alternatively to the overlapping or in additionthereto, it applies that at least one laterally defined region exists inwhich a sequence of materials along a vertical direction pointing awayfrom the substrate member is:

-   -   clear encapsulation material;    -   opaque coating material;    -   opaque encapsulation material.

Of course, the term “lateral” as used here indicates directions whichare parallel to a plane (lateral plane/horizontal plane) defined by thesubstrate member; and “vertical” indicates a direction perpendicular tosaid plane (and thus perpendicular to any lateral direction).

In some embodiments, the clear encapsulation material establishes anovermold for the one or more active optical components.

In some embodiments, the at least one laterally defined region laterallyencircles the at least one aperture.

Further embodiments emerge from the dependent claims and the figures. Aswill be appreciated, further features and details of the various aspectshave been described above and are described further below.

Below, the invention is described in more detail by means of examplesand the included drawings. The figures show schematically:

FIG. 1A a cross-sectional view an initial wafer;

FIG. 1B a cross-sectional view an initial wafer including an artificialwafer;

FIG. 1C a cross-sectional view an initial wafer including a contactingboard;

FIG. 1D a cross-sectional view an initial wafer including asemiconductor wafer;

FIG. 1E a cross-sectional illustration of a carrier assembly;

FIG. 2 a cross-sectional view of a resiliently coated wafer;

FIG. 3 a cross-sectional view of a clear encapsulation wafer;

FIG. 4 a cross-sectional view of the clear encapsulation wafer of FIG. 3and a replication tool;

FIG. 4A a cross-sectional view of a carrier assembly and of a mold formolding the clear encapsulation;

FIG. 5A a cross-sectional view of a step-structured wafer;

FIG. 5B a detail of the step-structured wafer of FIG. 5A in a top view;

FIG. 5C a cross-sectional view of a replication tool and of astep-structured wafer shaped by the replication tool;

FIG. 6A a cross-sectional view of a wafer in a not-finalized state,namely with unstructured opaque coating material on a surface of theclear encapsulation material;

FIG. 6B a cross-sectional view of an opaque coating wafer, as can beobtained by structuring the opaque coating material of the wafer of FIG.6A;

FIG. 6C a cross-sectional view of an opaque coating wafer having anopaque coating which is structured in a particular way;

FIG. 6D a top view of a detail of the opaque coating wafer of FIG. 6C;

FIG. 7 a cross-sectional view of a trenched wafer;

FIG. 8 a cross-sectional view of a detail of an opaque encapsulationwafer, e.g., as obtainable from the trenched wafer of FIG. 7 byapplication of an opaque encapsulation material;

FIG. 9 a cross-sectional view of a detail of a wafer with cuts in theopaque encapsulation, e.g., as obtainable from the opaque encapsulationwafer of FIG. 8;

FIG. 9A a cross-sectional view of a detail of a substrate arrangementwith furrows through the opaque encapsulation wafer, e.g., as obtainablefrom the opaque encapsulation wafer of FIG. 8;

FIG. 9B a schematized top view of a portion of the substrate arrangementof FIG. 9A;

FIG. 10 a cross-sectional view a detail of a wafer-level arrangement ofsingulated optical modules on which a spectral filter layer is present;

FIG. 11 a flow chart of an example of a method for manufacturing opticaldevices on wafer-level;

FIG. 12A a cross-sectional view of a single-channel optical devicedevoid a passive optical component and devoid a step structure of theclear encapsulation;

FIG. 12B a cross-sectional view of an optical device corresponding tothe one of FIG. 12A, but wherein the active optical component isresiliently encapsulated by a resilient encapsulation material;

FIG. 12C a cross-sectional view of an optical device corresponding tothe one of FIG. 12A, but wherein a passive optical component isestablished by the clear encapsulation material;

FIG. 12D a cross-sectional view of an optical device corresponding tothe one of FIG. 12C, but wherein the active optical component isincluded in a substrate part originating from an artificial wafer;

FIG. 12E a cross-sectional view of an optical device corresponding tothe one of FIG. 12A, but wherein the clear encapsulation is stepped;

FIG. 12F a cross-sectional view of an optical device corresponding tothe one of FIG. 12E, but including a passive optical component and aspectral filter layer;

FIG. 12G a cross-sectional view of a dual-channel optical deviceincluding one passive optical component per channel and having in bothchannels a step structure of the clear encapsulation;

FIG. 13A a cross-sectional illustration of a carrier assembly to which atemporary layer has been applied

FIG. 13B a cross-sectional illustration of a singulated modules obtainedby singulation on the temporary layer of FIG. 13A;

FIG. 14 a cross-sectional view of a detail of a clear encapsulationwafer on which spectral filter layer material is applied, according tothe “other variant” of the invention;

FIG. 15 a cross-sectional view of a detail of a clear encapsulationwafer on which a spectral filter layer is present, according to the“other variant” of the invention;

FIG. 16 a cross-sectional view of a detail of a trenched wafer,according to the “other variant” of the invention;

FIG. 17 a cross-sectional view of a detail of an opaque encapsulationwafer, e.g., as obtainable from the trenched wafer of FIG. 16 byapplication of an opaque encapsulation material, according to the “othervariant” of the invention;

FIG. 18 a cross-sectional view of a dual-channel optical deviceincluding no passive optical components and no baffles, according to the“other variant” of the invention;

FIG. 19 a flow chart of an example of a method for manufacturing opticaldevices on wafer-level according to the “other variant” of theinvention.

The described embodiments are meant as examples or for clarifying theinvention and shall not limit the invention.

In the following, a particularly elaborate method is described which hasvarious options and variants which can be but not necessarily need to bepart of the claimed invention.

By means of the described method, devices, more specifically opticaldevices, can be manufactured on wafer level.

All figures are schematical drawings only.

FIG. 1A depicts in a cross-sectional view an initial wafer 1 a includinga multitude of active optical components 2 and a wafer-size substrate 3.

Each of the active optical components 2 can be a light emitter, e.g., alight-emitting diode (LED), a vertical-cavity surface-emitting laser(VCSEL), an edge-emitting laser, an array of any of the precedingelements, and/or any combination of any of the preceding elements.

The light emitters can be operable to emit modulated light, such asspatially modulated light or temporally modulated light.

The light emitters can be operable to produce light of a particularrange of wavelengths, e.g., infrared light (IR), ultraviolet light (UV),or visible light. E.g., they can be operable to produce a selection ofone or more spans of infrared (IR) or of ultraviolet (UV) or of visiblelight.

In other cases, each of the active optical components 2 can be a lightdetector, e.g., a photodiode (PD), a complementarymetal-oxide-semiconductor device (CMOS device), a charge-coupled device(CCD), a demodulation pixel, an array of any of the preceding elements,and/or any combination of any of the preceding elements.

The light detectors can be operable to detect modulated light, such asspatially modulated light or temporally modulated light.

The light detectors can be operable to detect light of a particularrange of wavelengths, e.g., infrared light (IR), ultraviolet light (UV),or visible light. E.g., they can be operable to detect a selection ofone or more particular spans of infrared (IR) or of ultraviolet (UV) orof visible light.

It is noted that it is not excluded by the above that the active opticalcomponent 2 can be operable to emit and detect, respectively, also lightof further ranges of wavelengths (in addition to said particular rangeof wavelengths).

Said particular range of wavelengths can be, e.g., in the IR range,e.g., between 800 nm and 900 nm, such as in the range 850 nm±20 nm.

In case single-channel devices are manufactured, all active opticalcomponents 2 can be but do not have to be congeneric active opticalcomponents, e.g., either all light emitters or all light detectors.

In case of dual-channel devices, a portion of the active opticalcomponents 2 can be light emitters while another portion of the activeoptical components 2 can be light detectors. E.g., one half of themultitude of active optical components 2 can be light emitters and theother half can be light detectors.

The active optical components can be bare dies. In an alternative, theactive optical components 2 can be packaged components, e.g., chip-scalepackages.

Substrate 3 can have a very small thickness (vertical extension,z-height), e.g., of below 200 μm and even below 100 μm. In specificcases, the thickness can be below 70 μm or even below 50 μm.

In contrast to manufacturing methods which start with a thicker wafer tobe thinned during (or at the end of) the manufacturing method, such athinning step can possibly dispensed with, when starting with a thininitial wafer and with a thin substrate, respectively.

It can be provided that substrate 3 is not self-supporting. This can bedue to the choice of materials of substrate 3 and/or due to a lowthickness of substrate 3.

Substrate 3 can be plate-shaped. E.g., substrate 3 can have two opposingand mutually parallel substrate surfaces. A surface area of thesesubstrate surfaces can be larger than a surface area of any othersurface of the substrate. Substrate 3 can be devoid any openings.

Substrate 3 can include a contiguous dielectric body, e.g., a polymer orpolymer compound body, wherein the polymer can be, e.g., an epoxy resinor a polyimide. The body can be fiber-reinforced.

Substrate 3 can be a printed circuit board (PCB).

Active optical components 2 can be mounted on and electrically connectedto substrate 3, e.g., by wirebonds 4 or by solder balls (not illustratedin FIG. 1A).

In other cases, substrate 3 can include an artificial wafer. Theartificial wafer is composed of a multitude of semiconductor chips(e.g., of bare dies or chip-scale packages constituting the activeoptical components 2) which are mechanically interconnected to form acontiguous wafer by an interconnection frame 5, e.g., theinterconnection frame can be grid-shaped, with the active opticalcomponents 2 being located in (and filling) holes formed by the grid.Interconnection frame 5 can be made of a dielectric, e.g., of a polymermaterial, such as an epoxy resin.

Substrate 3 can includes the active optical components 2, and in thiscase, initial wafer 1 a can be identical with substrate 3. This can bethe case, e.g., when substrate 3 includes an artificial wafer.

FIG. 1B depicts in a cross-sectional view an initial wafer 1 a includinga multitude of active optical components 2 and a wafer-size substrate 3which includes an artificial wafer. The artificial wafer can bemanufactured using a molding process in which the active opticalcomponents 2 are at their vertical sides embedded in a molding compound,e.g., in the polymer material.

In other cases, substrate 3 can be a contact board. The contact board iscomposed of a multitude of electrically conductive plates 3 a, 3 b(e.g., of metal plates such as copper plates) which are mechanicallyinterconnected by an interconnection frame 3 c to form a contiguousplate-shaped board, e.g., similar to the interconnection frame 5 of theartificial wafer described in connection with FIG. 1B. Theinterconnection frame 3 c can describe a grid, with the electricallyconductive plates 3 a, 3 b located in (and filling) holes formed by thegrind. The interconnection frame 3 c can be made of a dielectric, e.g.,of a polymer material, such as an epoxy resin.

Like a wafer, also the contact board is a substantially disk- orplate-like shaped item, its extension (thickness) in one direction(z-direction or vertical direction) is small with respect to itsextension (width) in the other two directions (x- and y-directions orlateral directions or horizontal directions). The electricallyconductive plates 3 a, 3 b can extend fully across the thickness of thecontact board. The thickness of the contact board can be identical atthe electrically conductive plates 3 a and at the interconnecting frame3 c, however, this not necessarily has to be the case.

As illustrated in FIG. 1C, there can be two kinds of electricallyconductive plates: electrically conductive plates 3 a and electricallyconductive plates 3 b. Electrically conductive plates 3 a andelectrically conductive plates 3 b are mechanically interconnected witheach other but electrically insulated from each other by interconnectionframe 3 c.

On each electrically conductive plate 3 a, an active optical component 2is mounted, which can be in electrical and/or in thermal contact withthe respective electrically conductive plate 3 a. And each of the activeoptical components 2 is in electrical contact with one of theelectrically conductive plates 3 b, e.g., by a wirebond 4.

Electrically conductive plates 3 a can be solid metal plates. This canimprove heat dissipation from the respective active optical components 2connected thereto.

Electrically conductive plates 3 b can be solid metal plates, too.

The electrically conductive plates 3 a, 3 b can be consideredthrough-contacts or solid vias of the contact board.

In contrast to standard PCBs, the contact board can be devoid of anyconductor track in the sense of being devoid of any laterally runningelectrical connection present on a dielectric interconnection frameinterconnection frame 3 c, e.g., electrically interconnecting twothrough-contacts.

In other cases, substrate 3 can be a semiconductor wafer, e.g., asilicon wafer, including the active optical components 2, cf., e.g.,FIG. 1D.

When substrate 3 is a semiconductor wafer, initial wafer 1 a can beidentical with substrate 3.

The semiconductor wafer can be a single-piece semiconductor wafer.

The semiconductor wafer can have through-silicon vias (TSVs) such thatit has electrical connections between its main faces, i.e. across itsthickness.

FIG. 1D depicts in a cross-sectional view an initial wafer 1 a includinga multitude of active optical components 2 and a wafer-size substrate 3which is a semiconductor wafer.

In the following, for simplicity, initial wafer 1 a and substrate 3 willmostly be illustrated like depicted in FIG. 1A, wherein substrate 3constitutes, e.g., a PCB. However, other initial wafers 1 a andsubstrates 3, e.g., as depicted in FIG. 1B, could be applied in thefollowing, too, at least in most instances.

In FIG. 1D, a coordinate system indicating lateral directions x, y andvertical direction z is sketched which is applicable also to the othercross-sectional views.

During various processing steps, the initial wafer 1 a and its successorwafers (cf. below) can be attached to a carrier wafer, e.g., likeillustrated in FIG. 1E, to carrier wafer 6. A carrier assembly 66 inwhich a wafer to be processed is attached to a carrier wafer 6 cancontribute to minimizing stress to which the wafer is exposed. E.g.,bending of the wafer can be prevented to a large extent. The wafer, suchas initial wafer 1 a, can be attached to carrier wafer 6, e.g., by meansof a double-sided adhesive tape 65.

E.g., tape 65 can be a high-temperature tape, i.e. a tape which stronglyreduces its adhesive properties in reaction to application of heat.

Carrier wafer 6 can be rigid.

Carrier wafer 6 can be made of, e.g., glass.

As will be described below, the carrier assembly can remain assembled,e.g., up to a singulation step or more precisely up to a transfer of thewafer to another layer such as the temporary layer described furtherbelow on which the wafer will be separated into separate opticalmodules, e.g., by dicing.

For reasons explained below and as illustrated in FIG. 1E, it can beprovided that the carrier wafer 6 circumferentially laterally protrudesbeyond the wafer or the substrate 3, and it can also circumferentiallylaterally protrude beyond the tape 65. And furthermore, also tape 65 cancircumferentially laterally protrude beyond the wafer or beyond thesubstrate 3.

If initial wafer 1 a includes a substrate 3 on which active opticalcomponents 2 need to be assembled, e.g., by pick-and-place, theassembling can be accomplished while the substrate 3 is included in thecarrier assembly.

Alternatively, substrate 3 can be attached to an initial tape during theassembly.

In order to be able to process the assembled (initial) wafer while it isattached to carrier wafer 6 (so as to form carrier assembly 66), atransfer from the initial tape to carrier wafer 6 (or to tape 65) has tobe accomplished.

In order to minimize stress during such a transfer, bending of substrate3 and of the initial wafer 1 a, respectively, should be avoided as faras possible.

One way to accomplish this aim is to attach the initial wafer 1 a to aspecial vacuum chuck after assembly. The vacuum chuck has a plurality ofopenings at which an underpressure can be applied, and these opening aredistributed across the initial wafer 1 a. In addition, in a peripheralportion of the substrate, where no active optical components arepresent, the vacuum chuck can have one or more further openings at whichunderpressure can be applied and which can be arranged, e.g.,continuously or section-wise surrounding the active optical componentsof initial wafer 1 a.

In order to provide space where the openings can get in contact with thesubstrate 3, blank spaces can be provided on the substrate 3,interdispersed between the active optical components.

The openings can be located at ends of protruding portions of the vacuumchuck, so as to avoid undesired mechanical contacts between the vacuumchuck and the initial wafer, e.g., at the active optical components orat other parts not to be touched.

For facilitating alignment between the vacuum chuck and the initialwafer, alignment marks such as fiducials can be present at the initialwafer. The alignment marks can be viewed by one or cameras throughviewing openings of the vacuum chuck.

The transfer from the initial tape to the carrier wafer 6 (or to tape65) can be accomplished as follows: The vacuum chuck is laterallyaligned with respect to the initial wafer, e.g., by the aid of thealignment marks. Then, the vacuum chuck and the initial wafer (such assubstrate 3) are brought into contact, and underpressure is applied.

This way, initial wafer 1 a is held by the vacuum chuck, and the initialtape (present on the opposite side of substrate 3) can be removed. Theinitial tape can be, e.g., a UV tape which strongly reduces its adhesiveproperties in reaction to exposure to UV radiation. In that case,removal of the initial tape can be facilitated by UV irradiation.

Then, while still being held by the vacuum chuck, the carrier wafer 6can be attached to the initial wafer 1 a, e.g., by providing tape 65 inbetween them. Thereafter, the underpressure can be removed and thevacuum chuck can be removed from the initial wafer 1 a.

Even though, the wafer can be assembled in the carrier assembly 66during following processing steps, the carrier wafer 6 and tape 65 arein various cases not illustrated in the figures.

FIG. 2 depicts in a cross-sectional view a resiliently coated wafer 1 bobtained by applying a resilient encapsulation material 7 to the initialwafer 1 a (cf. FIG. 1A), thus producing a resilient encapsulation of theactive optical components 2. The resilient encapsulation can beoptional.

Resilient encapsulation material 7 is resilient and can thereforeprovide some protection for active optical components 2 and inparticular reduce mechanical stress exerted on active optical components2 and on electrical connections thereof such as on the wirebonds 4. Themechanical stress can be due to temperature changes in combination withdifferent coefficients of thermal expansion (CTEs) of the materialsinvolved and/or due to response of materials involved to changes inhumidity. The temperature changes and changes in humidity can occur,e.g., by heat treatments during further manufacturing steps or duringuse of the finished product. Another possible source of mechanicalstress can be stress occurring during de-molding in molding processespossibly carried out later, e.g., cf. the creation of the clearencapsulation and/or of the opaque encapsulation described furtherbelow. Still another possible source of mechanical stress can be stresscaused by dimensional change occurring as a consequence of a curingprocess such as of a curing of the clear encapsulation material and/orof the opaque encapsulation described further below.

Reducing the stress can increase manufacturing yield and reliability ofthe manufactured devices.

The resilient encapsulation material 7 can be an elastic material, suchas an elastic polymeric material, e.g., a silicone such as PDMS(polydimethylsiloxane). Other resilient materials can be used. too.

The resilient encapsulation material 7 is translucent to light of aparticular range of wavelengths emitted by or detectable by the activeoptical components 2.

As an option, resilient encapsulation material 7 can include spectrallyinfluencing material, such as light absorbing particles or pigmentsabsorbing light of wavelengths outside a particular range of wavelengthsemitted by or detectable by the active optical components 2, orspectrally selectively reflective particles.

This can in instances make a produced device less sensitive to incominglight of wavelengths not to be detected in case of detecting activeoptical components and/or narrow down a wavelength range emitted by anemitting active optical component if the device is an emitting activeoptical component. Accordingly, the clear encapsulation can establish anoptical filter.

The spectrally influencing material can in further instances effect adesired visual appearance of the resilient encapsulation material 7.

Application of resilient encapsulation material 7 can be accomplishedby, e.g., spray coating. E.g., a single or two (possibly even more thantwo) spray coating layers can be subsequentially applied, wherein thematerial can be hardened in a final hardening step, wherein one or moreintermediate hardening steps can be applied. E.g., each spray coatinglayer can be partially or fully hardened before application of a furtherlayer.

Evaporation or other ways of applying the resilient encapsulationmaterial 7 can be applied, too.

The hardening of the resilient encapsulation material 7 can beaccomplished by irradiation of resilient encapsulation material 7, e.g.,with ultraviolet (UV) light. An alternative or additional measure forhardening the resilient encapsulation material 7 can be to apply a heattreatment.

A layer thickness (averaged thickness) of each single spray coatinglayer can be, e.g., between 4 μm and 40 μm, more specifically between 8μm and 25 μm.

A layer thickness t of the resilient encapsulation can be, e.g., between5 μm and 50 μm, more specifically between 10 μm and 50 μm.

Independent of whether or not the optional resilient encapsulation hasbeen applied, the manufacturing method can continue with an applicationof a clear encapsulation to the initial wafer 1 a and to the resilientlycoated wafer 1 b, respectively.

For simplicity, the optional resilient encapsulation material 7 will notbe drawn in the following figures, at least in most instances—eventhough it may be present.

The clear encapsulation can be applied by applying to the wafer (1 a or1 b) a clear encapsulation material 8 which is translucent for light ofa the particular range of wavelengths.

The wafer obtained will be referred to as clear encapsulation wafer 1 c.

The clear encapsulation can provide protection for the active opticalcomponents 2, e.g., protection from mechanical damage and/or fromcontamination.

As an option, clear encapsulation material 8 can include spectrallyinfluencing material, such as absorbing particles or pigments, absorbinglight of wavelengths outside a particular range of wavelengths emittedby or detectable by the active optical components 2, or spectrallyselectively reflective particles.

This can make a produced device less sensitive to incoming light ofwavelengths not to be detected in case of detecting active opticalcomponents and/or narrow down a wavelength range emitted by an emittingactive optical component if the device is an emitting active opticalcomponent. Accordingly, the clear encapsulation can establish an opticalfilter.

The spectrally influencing material can in further instances effect adesired visual appearance of the clear encapsulation material 8.

FIG. 3 depicts in a cross-sectional view a clear encapsulation wafer 1c. As depicted in FIG. 3, the clear encapsulation can optionally includepassive optical components 9 which can be lens elements. The lenselements can be, e.g., refractive or diffractive orrefractive-and-diffractive lens elements. The passive optical components9 need not include lens elements, they can be, e.g., prisms or otherpassive optical components.

Each of the passive optical components 9 can be associated with one ofthe active optical components 2. This of course can include the casethat each of the passive optical components 9 is associated with two (oreven more) active optical components 2, and also the case that theinitial wafer 1 a includes, in addition to the passive opticalcomponents 9 associated with (at least) one active optical component 2,still further passive optical components (which are not associated withone of the active optical components 2).

Each of the passive optical components 9 can be aligned with respect toone of the active optical components 2, such as with respect to itsassociated active optical component 2.

Clear encapsulation material 8 can be a hardenable material such as acurable epoxy.

The clear encapsulation can be a unitary part and thus be a contiguouspiece. It can have wafer-size.

The clear encapsulation can have an interface with substrate 3. If clearencapsulation material 7 is present, to clear encapsulation can have inaddition or alternatively an interface with resilient encapsulationmaterial 7 (cf. FIG. 2), e.g., clear encapsulation material 7 can adheresolely to resilient encapsulation material 7.

The clear encapsulation can have a surface 10 opposite substrate 3 whichcan be structured, e.g., by including passive optical components 9, orwhich can be unstructured (“flat”).

Clear encapsulation material 8 can be applied in a replication processsuch as in a molding process, e.g., by vacuum injection molding (VIM).VIM is a known molding process in which the material to be molded isintroduced into a mold by the aid of an underpressure applied to themold.

In the replication process, the clear encapsulation material is shaped,e.g., while still being liquid or viscous, by means of a replicationtool such as by a mold. Thereafter, the clear encapsulation material ishardened, e.g., cured.

The hardening can be accomplished by applying a heat treatment and/or byirradiation of the clear encapsulation material 8, e.g., withultraviolet (UV) light.

The hardening can be accomplished from both sides, i.e., from thesubstrate side and from the side at which the clear epoxy is present.E.g., the hardening can include irradiation of the wafer with UV lightfrom both sides. This can be particularly beneficial in case the clearencapsulation material is applied in a rather thick layer and/or if theclear encapsulation material covers a side face of the carrier wafer(cf. below for details).

In some instances, when devices with a very low z-height aremanufactured, hardening (e.g., curing) by irradiation can effect that awarpage of the clear encapsulation wafer 1 c is possibly less pronouncedthan if the hardening includes a heat treatment.

For an enhanced mechanical and chemical stability during subsequentprocesses, clear encapsulation material 8 can be fully hardened at thispoint, e.g., fully cured.

It is possible to provide that the hardening of the clear encapsulationmaterial 8 is accomplished by irradiation only, i.e. without asupplemental heat treatment. This way, in some instances, an amount ofwarpage of the clear encapsulation wafer 1 c can be kept low. Of course,the irradiation itself can induce some heat, but this is not considereda heat treatment. In some instances, in a heat treatment, temperaturesof above 80° C., e.g., of above 100° C. are applied.

FIG. 4 depicts the clear encapsulation wafer 1 c of FIG. 3 and a portionof a replication tool 11 operable to shape clear encapsulation wafer 1 cof FIG. 3, drawn in a distance to surface 10 of the clear encapsulationsuch as like removed from the clear encapsulation material 8 afterhardening the same.

Replication tool 11 includes a multitude of shaping sections 12, whereineach of the shaping sections 12 has a shaping surface 13 being anegative replica of a surface of one of the passive optical components9.

The replication tool 11 can be unstructured, i.e. flat, if no passiveoptical components are to be produced in the clear encapsulationmaterial 8 during the replication process. Surface 10 can be flat(unstructured) in that case.

During the replication process, substrate 3 can be supported by thecarrier wafer (not illustrated).

FIG. 4A is a cross-sectional view of a carrier assembly and areplication tool (such as a mold) for producing/shaping the clearencapsulation. The tool includes one or more side parts 11 b and a toppart 11 a which can abut one another during the molding.

The open arrow indicates that clear encapsulation material can enter aspace formed between the tool and the carrier assembly. Due to thespecial, pyramid-like layered structure of the carrier assembly, asurface 83 of the tape 65 and a portion 82 of an upper face of carrierwafer 6 and a side face 81 of carrier wafer 6 are exposed to can becovered by the clear encapsulation material. This can result in a verystable interconnection of the clear encapsulation with the tape 65 andin particular with carrier wafer 6. The good anchoring of the clearencapsulation in the peripheral portions of the carrier assembly canmake the clear encapsulation wafer relatively insensitive to variousstresses such as to heat-induced stress. And potential delaminationproblems of the clear encapsulation can also be strongly reduced thisway.

A special feature of the replication tool is that it includes the toppart 11 a and the one or more side parts 11 b which aredetachable/removable from one another. This way, top part 11 a can beremoved from the clear encapsulation (e.g., after the hardening) in adirection opposite to the direction along which the one or more sideparts 11 b can be removed from the clear encapsulation (e.g., after thehardening).

In some embodiments, the replication tool includes merely a single sidepart 11 b (e.g., in addition to a top part). It can be, e.g., ringshaped. Side part 11 b can be a unitary part (a single-piece part).

As illustrated in FIG. 4A, side part 11 b can have a chamfered sideshaping surface 11 c. Surface 11 c is chamfered to open up in adirection opposite to the direction of removal of the side part 11 b.During molding, side shaping surface 11 c is in contact with the clearencapsulation material.

The side shaping surface 11 b can be free from surface sections facingin a direction having a component running into a vertical directionpointing from the substrate 3 to the carrier wafer 6 (in the moldingposition).

Applying the clear encapsulation can include, accordingly,

-   -   arranging the side part 11 b and the carrier assembly in a        molding position in which the side part 11 b surrounds (more        specifically: laterally surrounds) the carrier assembly such        that the side shaping surface is chamfered to open up in a        vertical direction pointing from the carrier wafer 6 to the        substrate 3; and    -   shaping the clear encapsulation material by means of the side        shaping surface 11 b while maintaining the molding position.

After shaping the clear encapsulation material by means of thereplication tool, the clear encapsulation material can be hardened(while maintaining the molding position.)

The chamfered shape of the side shaping surface 11 c can reducemechanical stress to which the carrier assembly (and in particular theclear encapsulation wafer) is exposed when the replication tool (and inparticular when the side part 11 b) is removed from the hardenedencapsulation material.

Also for the opaque encapsulation material described in more detailbelow, a replication tool with corresponding properties (separable topand side part; chamfered side shaping surface) can be used.

In a subsequent step, an opaque coating is applied on the surface 10 ofthe clear encapsulation (cf. below for details concerning the opaquecoating). And in a still further step, this opaque coating is exerted tostress which potentially can cause cracks in the opaque coating and/ordelamination of the opaque coating from the clear encapsulation. Apossible source of the stress can be the creation of trenches in theclear encapsulation (cf. below for details concerning the trenches), inparticular wherein the opaque coating is cut through for creating thetrenches.

For avoiding delamination and/or cracks in certain areas of the opaquecoating, e.g., in areas where the opaque coating defines apertures (cf.below for details concerning the apertures), precautious measures can betaken.

One such measure is to provide that surface 10 of the clearencapsulation has a stepped structure. Propagation of cracks anddelamination can be stopped at steps. Accordingly, steps can makepossible to avoid or at least reduce the probability of emergence ofcracks or delamination in certain areas. Therefore, the steppedstructure establishes steps at surface 10.

Surface 10 can have depressions and/or protrusions delimited by steps.

E.g., surface 10 can have grooves.

FIG. 5A depicts in a cross-sectional view a wafer referred to asstep-structured wafer 1 d having a stepped structure. FIG. 5B depicts adetail of the step-structured wafer 1 d of FIG. 5A in a top view.

In the example of FIGS. 5A, 5B, the stepped structure includesdepressions 17 in form of grooves 19 which establish steps 18, the stepsrunning along step lines 20. The step lines 20 (drawn as thick dottedlines in FIG. 5B) can be straight lines. The grooves 19 can define arectangular grid.

Of course, other distributions and shapes of depressions and/orprotrusions and also of grooves, if present, can be implemented.

A step height h of the steps can be between 5 μm and 50 μm, inparticular between 10 μm and 30 μm. In relation to a thickness d (cf.FIG. 6B) of the above-mentioned and below-described opaque coating 23which is later on applied on surface 10, it can apply that step height his at least three times or at least four times thickness d. It can applythat step height h is between two times thickness d and ten timesthickness d, or height h is between three times thickness d and eighttimes thickness d.

With reference to the above-mentioned and below-described trenches andapertures, it can be provided that between each of the apertures and anyof the trenches, there is a step line present along which surface 10 isstepped. E.g., said trenches can run within the grooves 19, having asmaller width than the grooves.

The grooves 19 can have a width of between 50 μm and 1000 μm, e.g.,between 150 μm and 800 μm.

The stepped structure and thus, e.g., the grooves 19, can be created byremoving a portion of the clear encapsulation material 8 after the clearencapsulation material 8 has been applied and hardened. This can beaccomplished, e.g., by means of a dicing saw. E.g., the depth by whichblades of the dicing saw enter the clear encapsulation material 8 can beadjusted to produce a desired step height h, a width of the dicingblades can be selected to produce a desired groove width, and sawinglines along which the blades remove material from the clearencapsulation can be selected to produce steps along desired step lines.An alternative to dicing with a dicing saw can be, e.g., abrasive waterjet ablation, laser ablation, or grinding.

Another way of creating the stepped structure is to create the steppedstructure already when applying the clear encapsulation material 8.E.g., if the clear encapsulation material is shaped in a replicationprocess, the corresponding replication tool can be structured to produce(in the replication process) the stepped structure. In instances, thiscan simplify the manufacturing process, e.g., by eliminating a step suchas the before-described step of removing a part of the clearencapsulation material 8 for creating the stepped structure.

FIG. 5C depicts a replication tool 21 structured for producing a steppedstructure in the clear encapsulation, along with a so-obtainedstep-structured wafer 1 d which can have the same shape asstep-structured wafer 1 d of FIG. 5A. Replication tool 21 can be similarto replication tool 11 of FIG. 4 in that both are structured forproducing passive optical components 9 (which merely is an option), butreplication tool 21 is, unlike replication tool 11, structured forproducing the stepped structure of the clear encapsulation. Inparticular, replication tool 21 can therefor have protrusions 22, andthus, e.g., protrusions 22 for producing grooves 19.

Replication tool 21 can be used in a molding process, e.g., in a VIMprocess as described above.

Another way of avoiding delamination and/or cracks in certain areas ofthe opaque coating, which can be an alternative or an additional measureto the above-described provision of a stepped structure in the clearencapsulation, is based on a particular way of structuring the opaquecoating and will be described further below.

In a subsequent step, an opaque coating is applied to the clearencapsulation. A function of the opaque coating is to define apertures,wherein each aperture is associated with one of the active opticalcomponents and aligned accordingly.

Each aperture, i.e. each opening, can be delimited by a stop, whereinthe stops are included in the opaque coating. Even though in the presentpatent application it is mostly referred to the apertures, it would alsobe possible to refer to the material structures delimiting theapertures, i.e. to the stops included in the opaque coating.

Each aperture can be provided for delimiting a light cone of lightemitted from and of light to be detected by one (or more) of the activeoptical components, respectively. This does not exclude the case thatthere are further apertures which provide and additional delimiting ofthe same light cone(s).

It is possible that active optical components can be present which arenot associated with one of the apertures, and it is also possible thattwo (or even more) active optical components are associated with asingle aperture. There can, however, be a one-to-one relation betweenapertures and active optical components, i.e. each aperture isassociated with no more than exactly one active optical component and,vice versa, each active optical component is associated with no morethan exactly one aperture.

FIG. 6B depicts in a cross-sectional view an opaque coating wafer 1 e.In the depicted example, step-structured wafer 1 d of FIG. 5A includingpassive optical components 9 is the underlying wafer onto which anopaque coating 23 has been applied. However, it is also possible toapply the opaque coating 23 on an unstepped wafer (not including thestepped structure, e.g., as shown in FIGS. 3, 4) and/or to a wafer notincluding any passive optical components 9, and thus even to anunstructured wafer including neither the stepped structure nor thepassive optical components 9 in the clear encapsulation.

The opaque coating 23 is opaque to light of a particular range ofwavelengths emitted by or detectable by the active optical components 2.

One way to produce a structured opaque coating, e.g., like the oneillustrated in FIG. 6B, is to use a photostructurable material. E.g.,the photostructurable material is applied across the underlying wafer,and then selectively irradiated and thereafter developed.

For example, a resist material (such as a photoresist material) can beused, but also other photostructurable materials can be used.

FIG. 6A depicts in a cross-sectional view a state of the wafer beforethe opaque coating 23 is finalized, namely a state after applying anopaque coating material 24 to surface 10 of clear encapsulation material8. In FIG. 6A, opaque coating material 24 is still unstructured.Thereafter, it is structured in order to produce a multitude ofapertures 25 and thus to create opaque coating 23 as depicted in FIG.6B.

The opaque coating material 24 can be spray-coated onto the clearencapsulation material 8. Other ways of applying opaque coating material24 can be used, e.g., spin coating.

The opaque coating material 24 can be structured, e.g., by selectiveillumination by means of, e.g., laser direct imaging (LDI) or using amask.

Developing the selectively illuminated opaque coating material 24 can beaccomplished, e.g., by spinning, i.e. by rotating the wafer whileapplying a suitable developer (e.g., a liquid developer) onto theapplied opaque coating material 24. Other ways of developing theselectively illuminated opaque coating material 24 are possible, too.

If passive optical components 9 are present in the clear encapsulationmaterial 8, as is illustrated, e.g., in FIGS. 6A, 6B, each of thepassive optical components 9 can be associated with one of the apertures25. E.g., each passive optical component 9 can be centered with respectto its associate aperture 25.

For producing well-defined and well-aligned apertures 25, it can be ofadvantage to define the apertures 25 in a particularly thin opaquecoating material 24.

Photolithograhic structuring can be accomplished with high precisionwhich can be beneficial for producing well-defined and/or smallapertures.

The thickness d of the opaque coating 23 can be, e.g., between 0.5 μmand 10 μm and more particularly between 1 μm and 8 μm, e.g., between 2μm and 6 μm.

As has been announced above, another way of avoiding delamination and/orcracks in certain areas of the opaque coating, will be described in thefollowing. This can be an alternative to the above-described provisionof a stepped structure in the clear encapsulation or be a measureapplied in addition thereto.

It is possible to apply a particular way of structuring the opaquecoating 23, namely, e.g., in such a way that regions are produced whichare free of the opaque coating 24 and which (fully or partially)surround the areas to be “protected” such as the areas where theapertures 25 are defined by the opaque coating 23.

FIG. 6C depicts in a cross-sectional view an opaque coating wafer 1 ehaving a suitably structured opaque coating 23. FIG. 6D depicts a detailof the opaque coating wafer 1 e of FIG. 6C in a top view.

The opaque coating 23 of FIGS. 6C, 6D is similar to the one of FIG. 6B,but it includes regions 26 which are free of the opaque coating material24—in addition to the apertures 25.

Regions 26 can be produced during structuring the applied opaque coatingmaterial 24, e.g., by suitably illuminating (and developing) the appliedopaque coating material 24.

In FIG. 6D, also trenches 27 are depicted by means of which side wallsof intermediate products are created, as will be described below (cf.FIG. 7). As illustrated in FIG. 6D, the trenches 27 can run inside theregions 26. Thus, in the example of FIG. 6D, the trenches 27 do not runthrough the opaque coating 23. This can be the case, but does notnecessarily have to be the case.

And regions 26 can be located within depressions 17 and grooves 19,respectively, as illustrated in FIG. 6C.

It can be provided, that each of the apertures 25 is separated from anyof the trenches 27 (to be produced, cf. below) by at least one region 26which is free of the opaque coating material 24. This provided, trenches27 can run, at least in part, through opaque coating material 24 ofopaque coating 23.

For various applications, it can be of advantage to keep as muchundesired stray light out of the produced optical device as possibleand/or to keep light as completely as possible from exiting the devicealong undesired paths.

This is one possible reason for the following subsequent manufacturingsteps in which side walls are produced by producing trenches extendingthrough the clear encapsulation and covering the side walls by an opaqueencapsulation material.

Another possible reason for those subsequent manufacturing steps is thatreliability and/or mechanical stability of the finished product possiblycan thereby be enhanced.

For simplicity, the further steps will, at least in part, be illustratedwith opaque coating wafer 1 e of FIG. 6B as underlying wafer. However,the steps can also be accomplished based on other wafers.

In a first subsequent step, a trenched wafer 1 f is produced like theone depicted in a cross-sectional view in FIG. 7. Trenched wafer 1 f isproduced by creating trenches 27 which extend fully through the clearencapsulation. The trenches 27 can, as illustrated in FIG. 7, extendpartially into substrate 3.

In order to preserve cohesion of the trenched wafer 1 f and preserve aprecise relative positioning of the separate portions of clearencapsulation material 8, it can be provided that the trenches 27 do notextend fully through substrate 3.

Having the trenches 27 extending partially into substrate 3 can help toachieve a good light-tightness in the respective locations nearsubstrate 3, as will become clear further below.

Trenches 27 can extend into substrate 3 by between 0 μm and 50 μm, moreparticularly between 2 μm and 30 μm, e.g., between 5 μm and 25 μm. Sidewalls 30 can be vertically aligned walls.

Trenches 27 can extend into substrate 3 by between 5% and 75%, moreparticularly between 10% and 50%, e.g., between 15% and 35% of thethickness of the substrate 3.

Trenches 27 can be produced by, e.g., sawing, e.g., using a dicing saw.Care has to be taken when adjusting the depth to which blades of thedicing saw remove material.

Producing the trenches 27 creates side walls 30 in the clearencapsulation. Side walls 30 can be vertically aligned walls. Producingthe side walls 30 can also be understood as producing a multitude ofintermediate products 28. Therein, each intermediate product can includea portion of the clear encapsulation, one (or more) of the activeoptical components 2 and the respective associated aperture 25. Thelatter does not exclude that there are some of the intermediate products28 which do not include an aperture and neither that there areintermediate products which include two (or more) apertures.

Each intermediate product can also include at least one, in particularat least three, e.g., four of the side walls 30.

Producing the side walls 30 can more specifically also be understood asproducing a wafer-level arrangement 29 of intermediate products 28.

A wafer-level arrangement of items means that there is a multitude ofitems which have fixed relative positions (across the wafer such asacross trenched wafer 1 f). E.g., keeping the items (the intermediateproducts 28) in place to have constant relative positions (at leastlaterally) can be accomplished by substrate 3—at least if substrate 3 isnot divided into separate parts, e.g., by producing trenches 27.

A finally produced device can include one or more intermediate products28. E.g., in case of a single-channel device, it can include, e.g., nomore than a single intermediate product 28. And, e.g., in case of adual-channel device, it can include, e.g., no more than exactly twointermediate products 28, e.g., which can be neighboring intermediateproducts 28 in the wafer-level arrangement 29.

As has been described above, producing trenches 27 can induce cracks ordelamination in opaque coating 23. Various measures that can be taken toavoid that the apertures 25 deteriorate because of such cracks ordelaminations have been described above.

Exemplary possible positions of trenches have been depicted in FIG. 6D.

Trenches 27 can define a rectangular grid.

As is clear from the examples, it can be provided that each trench 27lies (with respect to its lateral position and extension) within one ofthe depressions 17, e.g., within one of the grooves 19.

As is clear from the examples (cf. FIG. 6D), it can be provided thateach trench 27 lies (with respect to its lateral position and extension)within one of the regions 26.

Of course, plenty variations are possible here.

A width of the trenches 27 can be, e.g., between 50 μm and 1000 μm, moreparticularly between 100 μm and 600 μm.

In a further subsequent step, trenches 27 are filled by an opaqueencapsulation material.

FIG. 8 depicts in a cross-sectional view a detail of an opaqueencapsulation wafer 1 g which can be obtained by applying to a trenchedwafer 1 f, such as to trenched wafer 1 f of FIG. 7, an opaqueencapsulation material 31. The trenches 27 created before (cf. FIG. 7)can be filled by the application of the opaque encapsulation material31.

FIG. 8 illustrates that opaque encapsulation material 31 can be appliedto the wafer-level arrangement 29 of intermediate products 28 depictedin FIG. 7.

This way, the side walls 30 of the intermediated products 28 are coveredby opaque encapsulation material 31.

Each intermediate product 28 can be laterally surrounded by opaqueencapsulation material 31.

Each active optical component 2 can be laterally surrounded by opaqueencapsulation material 31.

Space present between mutually opposing side walls of neighboringintermediate products 28 can be filled, in particular completely filled,with opaque encapsulation material 31.

The opaque encapsulation material 31 is opaque to light of a particularrange of wavelengths emitted by or detectable by the active opticalcomponents 2.

After applying the opaque encapsulation material 31, it is hardened,e.g., cured. Thereby, it can become rigid.

Opaque encapsulation material 31 can be a polymer-based material whichcan be hardened, e.g., cured, wherein the hardening can be accomplishedby, e.g., applying energy to the material, e.g., in form of heat and/orin form of radiation. For example, opaque encapsulation material 31 caninclude an epoxy resin such as a curable epoxy.

The hardening, e.g., curing process can be accomplished so as to achievethat the opaque encapsulation material 31 thereby is completely hardenedand fully cured, respectively, at this point

The hardening process can include a heat treatment, e.g., an applicationof a temperature of at least 100° C., e.g., of at least 110° C., such asbetween 110° C. and 140° C. for a duration of, e.g., at least 10 min,such as between 10 min and 60 min.

It can be provided that no heat treatment is applied in the describedmanufacturing process (starting with the initial wafer 1 a) before thehardening process of the opaque encapsulation material 31. This can makepossible to reduce warpage of the wafer before application of the opaqueencapsulation material 31.

In addition to the heat treatment, irradiation, e.g., with UV radiation,can be applied. This can accelerate the hardening process.

The so-obtained opaque encapsulation 32 can contribute tolight-tightness of the final product (in places where desired) and canalso enhance mechanical stability of the final product, as will becomeclearer further below.

The application of opaque encapsulation material 31 can be accomplishedin such a way that the apertures 25 remain free of opaque encapsulationmaterial 31.

The opaque encapsulation material 31 can be applied in such a way thatthe opaque encapsulation 32 together with the opaque coating 23 ortogether with parts of the opaque coating 23 constitute a contiguouspart.

The opaque encapsulation 32 and the opaque coating 23 together can forma contiguous opaque shell for each intermediate product 28, wherein eachof the shells contains (on its inside) the respective portion of theclear encapsulation material 8, and each of the shells defines (via theopaque coating 23) a respective aperture 25.

Opaque encapsulation 32 and opaque coating 23 can be mutually abuttingand/or overlapping. They can be mutually abutting and/or overlapping foravoiding the presence of slits between opaque encapsulation 32 andopaque coating 23 through which light of said particular range ofwavelengths could pass.

Having an overlap between opaque encapsulation 32 and opaque coating 23can contribute to a safer manufacturing process in terms of avoidingsaid slits.

Without overlap, the application of the opaque encapsulation material 31must be very well controlled in order to prevent formation of slits,e.g., from air inclusions or voids where opaque encapsulation 32 andopaque coating 23 should be abutting.

One way of applying opaque encapsulation material 31 is to do it in areplication process such as in a molding process. E.g., opaqueencapsulation material 31 can be applied by vacuum injection molding(VIM).

In FIG. 8, opaque encapsulation wafer 1 g is depicted along with areplication tool 33 operable to shape opaque encapsulation material 31.

Like explained above for the shaping by replication of the clearencapsulation, also the opaque encapsulation can be shaped by means of areplication tool including one or more side parts having a chamferedside shaping surface (cf. item 1 c in FIG. 4A). Likewise, this canprovide an improved anchoring of the opaque encapsulation to the clearencapsulation. This can reduce the exposure of the wafer to mechanicalstress. FIG. 9A (cf. below) illustrates an example of a resulting opaqueencapsulation.

And, the hardening of the opaque encapsulation material can beaccomplished from both sides, i.e., from the substrate side and from theside at which the clear epoxy is present. E.g., the hardening caninclude irradiation of the wafer with UV light from both sides and/orinclude application of heat from both sides. This can be particularlybeneficial in case the opaque encapsulation material is applied in arather thick layer and/or if the opaque encapsulation material covers aside face of the carrier wafer and/or a face of the clear encapsulationcovering a side face of the carrier wafer.

Replication tool 33 can include at least one resilient inner wall 34.The opaque encapsulation material 31 can be shaped by the resilientinner wall 34 or, more particularly, by a replication surface 36constituted by a surface 35 of the resilient inner wall 34. In thatcase, replication tool 33 can also be referred to as a resilientreplication tool 33. In addition, replication tool 33 can include arigid back 37 as a mechanical support for resilient inner wall 34.

During shaping the opaque encapsulation material 31, the replicationsurface 36 can be contact with the opaque coating material 31 in orderto shape it.

Resilient inner wall 34 can be made of an elastic polymeric material,e.g., of a silicone, e.g., of PDMS. In instances, the provision of aresilient inner wall 34 can enhance yield and/or manufacturability, inparticular for very thin trenched wafers 1 f.

During the replication process, substrate 3 can be supported by thecarrier wafer, cf. above for details (not illustrated in FIG. 8).

The resilience of resilient inner wall 34 can, to some extent, adapt towarpage of trenched wafer 1 f and of opaque encapsulation wafer 1 gwhich can contribute to minimizing crack formation and delamination.

CTE mismatch problems occurring as a consequence of a heat treatment forhardening the opaque encapsulation material 31 and other sources ofmechanical stress to which the wafer (trenched wafer 1 f or opaqueencapsulation wafer 1 g) is exposed can be mitigated by the resilienceof resilient inner wall 34.

If wafer-level arrangement 29 of intermediate products 28 is suitablydesigned, as is the case in the example depicted in FIG. 8, replicationtool 33 can be unstructured, i.e. flat. Surface 35 can be flat in thatcase.

Alternatively, it can be provided that replication tool 33 includes amultitude of shaping sections, wherein each of the shaping sections hasa structured surface.

A possible function of replication tool 33 is to avoid an entry ofopaque encapsulation material 31 into any of the apertures 25 and, ifpresent, onto any of the passive optical components 9.

The resilience of resilient inner wall 34 can support this function.

As symbolized in FIG. 8 by the open arrow, surface 35 of replicationtool 33 (more specifically: of resilient inner wall 34) is pressedagainst trenched wafer 1 f during application of opaque encapsulationmaterial 31, and more specifically, surface 35 is in direct contact witha sections 42 of opaque coating 23.

The pressure applied can be due to an underpressure applied for the VIMprocess. Alternatively or in addition, further pressure can be applied(externally). This way, sections 42 of opaque coating 23 and sections 43of surface 35 of replication tool 33 can, together, form a seal 41,wherein the seal 41 cannot be crossed by opaque encapsulation material31 during its application to trenched wafer 1 f.

The seal 41 can prevent opaque encapsulation material 31 from spreadingthrough the seal 41 from one side of the seal 41 to the other side ofthe seal 41.

During the pressing, a multitude of hollows 44 can be established, and amultitude of the seals 41 can be established, wherein each of the seals41 completely (laterally) surrounds one of the hollows 44.

The seals 41 can prevent that any of the opaque encapsulation material31 enters the respective surrounded hollow 44, wherein each of thehollows 44 can enclose one of the apertures 25. If passive opticalcomponents 9 are provided, they can be enclosed by the hollow, too. Andeach of the seals 41 can be formed by a respective section 42 of theopaque coating 23 abutting a respective section 43 of the surface 35 ofreplication surface 33. Around each of the hollows 44, a seal 41 can beformed by a section of the opaque coating 23 abutting a section of thesurface 35 of the replication tool 33.

Each of the hollows 44 can be confined by

-   -   a portion 45 of the surface 10 of the clear encapsulation        material 8, wherein this portion can (but does not have to)        include a surface portion of a passive optical component 9,        e.g., a lens surface;    -   a portion 46 of the opaque coating 23; and    -   a portion 47 of the surface 35 of replication tool 33.

It can be provided that the hollows are confined by no more than thesethree items.

Each of the hollows 44 can be hermetically closed with respect topenetration of the opaque encapsulation material 31 during theapplication of the opaque encapsulation material 31.

As shown in, e.g., FIGS. 7, 8, it can be provided that for each passiveoptical component 9, a point of the respective passive optical component9 most distant from substrate 3 is closer to substrate 3 than a point ofthe clear encapsulation material 8 which is most distant from substrate3, or at least than a point of the opaque coating 23 which is mostdistant from substrate 3.

Similarly, it can be provided that no part of the passive opticalcomponents 9 extends (in a direction pointing from substrate 3 to opaquecoating 23) beyond opaque coating 23.

In these cases, for example, an unstructured replication tool 33 (with aflat surface 35) can be used, making possible that precision alignmentsteps for laterally adjusting replication tool 33 with respect totrenched wafer 1 f can be dispensed with.

However, if parts of passive optical components (or even other parts ofclear encapsulation material 8) extend beyond opaque coating material24, hollows and seals can be formed during application of opaqueencapsulation material 31 (for keeping apertures 25 and passive opticalcomponents 9 free from the opaque encapsulation material 31) by using asuitably structured replication tool. E.g., such a replication tool canbe structured to include openings to be laterally aligned with respectto the apertures (in a distance to substrate 3 greater than a distanceto substrate 3 of the apertures 25), so as to accommodate said parts ofthe passive optical components 9.

In view of heat treatments to follow afterwards and consequentialdimensional problems (e.g., CTE mismatch problems) potentially resultingin warpage, delamination, cracking, but also in order to relax stressesalready present in the opaque encapsulation wafer 1 g, e.g., due to aheating treatment for hardening the opaque encapsulation material 31,the following measures relating to cuts in the opaque encapsulation canbe taken.

For one or more of the reasons above, cuts 48 can be produced in opaqueencapsulation material 31. Those cuts 48 do not segment substrate 3 oropaque encapsulation 32 (and neither the wafer-level arrangement 29 ofintermediate products 28).

FIG. 9 depicts in a cross-sectional view a detail of a wafer 1 h withcuts 48 which can be obtained, e.g., from opaque encapsulation wafer 1 gof FIG. 8. The cuts 48 can be produced, e.g., by laser cutting or usinga dicing saw.

When applying the opaque encapsulation 32 using a replication tool suchas a mold, cf., e.g., FIG. 8 item 33, the opaque encapsulation wafer 1 gcan remain attached to the replication tool, so that the opaqueencapsulation wafer 1 g is mechanically supported, and its constituentskeep their relative positions during application of opaque encapsulation32. Applying a vacuum and/or mechanical clamping, for example, can beapplied for ensuring that the opaque encapsulation wafer 1 g remainsattached to the replication tool.

Before producing cuts 48, replication tool 33 is removed in order togive access to the upper face of opaque encapsulation wafer 1 g (whichis opposite substrate 3) for producing the cuts 48. During this,mechanical support continues being provided by the rigid carrier wafer(not illustrated in FIG. 9).

The cuts 48 can run along the trenches 27 in the clear encapsulationmaterial 8, and they can run inside the trenches 27.

They can define a rectangular grid.

The cuts 48 can run along cut lines which are aligned with respect tothe trenches 27, e.g., centered with respect to the trenches 27.

The cuts 48 can be very narrow. A width of the cuts 48 can be, e.g.,between 1 μm and 500 μm, more particularly between 5 μm and 300 μm.

When the cuts 48 run along the trenches 27, they can have a (lateral)width of less than the width of the trenches 27. E.g., they can have awidth of at most, e.g., 0.8 times a width of the respective trench 27(where the cut is located) or, e.g., of at most 0.5 times said width ofsaid respective trench 27.

A penetration depth of the cuts 48 into the opaque encapsulationmaterial 31 can be, e.g., between 5 μm and 1000 μm, in instances between50 μm and 300 μm. This can depend on, e.g., material properties and ontemperatures applied during the processing.

It can be provided that the cuts 48 do not extend into the clearencapsulation material 8, i.e. that clear encapsulation material 8 canremain uncut while applying the cuts.

After producing cuts 48, the opaque encapsulation 32 still fully coversall the side walls 30 of the intermediate products.

The cuts 48 can be produced before a singulation step in whichsingulated optical module are produced. Cf. below for a singulationstep, e.g., FIG. 10. And the cuts 48 can be produced before a furtherheat treatment is applied, wherein said further heat treatment isapplied before the singulation step.

Another option can be to produce one or more furrows extending (fully)through the opaque encapsulation wafer 1 g and (fully) through the wafer1 h with cuts, respectively. Such a furrow 70 is illustrated in across-sectional view in FIG. 9A. The furrow 70 extends (fully) throughthe opaque encapsulation material 31, (fully) through the clearencapsulation material 8 and (fully) through the substrate 3. Furrow 70can partially extend into or even extend (fully) through the wafer 1 gand 1 h, respectively.

The one or more furrows 70 can laterally surround, e.g., fully surround,an area in which all intermediate products are arranged. This isillustrated in a top view in FIG. 9B. Thus, all optical modules to besingulated (illustrated as small squares in FIG. 9B) can be locatedlaterally inside a line described by the one or more furrows 70.

The one or more furrows 70 can contribute to minimizing stress to whichthe wafer is exposed when it is removed from the tape 65 (and fromcarrier wafer 6), e.g., before singulation. The furrows 70 can providesome guidance to the wafer (or wafer part) during its removal from thetape 65 (in a direction parallel to a vertical direction). And it can be(at least partially) prevented that deformations originating inperipheral portions 63 detrimentally influence the inner portion of thewafer and thus also the optical modules to be singulated.

The one or more furrows 70 can extend into the substrate 3, e.g.,through substrate 3.

The one or more furrows 70 can extend into the tape 65, e.g., throughtape 65.

Accordingly, as a step subsequent to producing cuts 48 in the opaqueencapsulation (and, if present, the furrows 70) described above, anotherheat treatment can optionally be applied, such as for the purpose ofstrengthening an adhesion of the opaque coating 23 to the clearencapsulation material 8. A too small adhesion of the opaque coating 23to the clear encapsulation material 8 can result in delamination of theopaque coating 23 from the clear encapsulation material 8 during asubsequent singulation step in which singulated optical module areproduced.

With the above-described cuts provided, a warpage of the wafer 1 hbefore the heat treatment is quite low (low enough to ensure no or onlylittle delamination) and can remain quite low (low enough to ensure noor only little delamination) during the heat treatment and duringcooling down after the heat treatment.

The sequence (order) of

-   -   applying a heat treatment for hardening the opaque encapsulation        material 31, then    -   producing the cuts (and optionally also the furrows 70), and        then    -   the heat treatment for enhancing an adherence of the opaque        coating 23 to the clear encapsulation material 8

(all this before the singulation described below) can make possible toproduce products with no or only little delamination, to achieve a highproduction yield, and to produce products of high reliability.

During the heat treatment for strengthening the adhesion of the opaquecoating 23 to the clear encapsulation material 8, a temperature of above100° C. such as a temperature of between 110° C. and 160° C., e.g.,between 115° C. and 150° C. can be applied.

It can be provided that the temperature applied is at least as high asthe temperature applied for hardening the opaque encapsulation material31.

The heat can be applied for a duration of between 5 min and 120 min,e.g., for between 10 min and 60 min.

The heat can be applied, e.g., for at least 10 min.

The heat can be applied, e.g., for at most 50 min.

It can be provided that no heat treatment is applied in the describedmanufacturing process after the hardening process of the opaqueencapsulation material 31 and before the heat treatment for thestrengthening the adhesion of the opaque coating 23 to the clearencapsulation material 8.

And it can, e.g., at the same time be provided that no heat treatment isapplied in the described manufacturing process (starting with theinitial wafer 1 a) before the hardening process of the opaqueencapsulation material 31.

In the already announced singulation step, the wafer (opaqueencapsulation wafer 1 g, or wafer 1 h with cuts 48 and optionally withfurrows 70, with our without having been subjected to the the heattreatment for the strengthening the adhesion of the opaque coating 23 tothe clear encapsulation material 8) is singulated to produce singulatedoptical modules.

In particular, a wafer-level arrangement of singulated optical modulescan be obtained this way.

In FIG. 9, places where the wafer (in the illustrated case wafer 1 hwith cuts 48) is segmented (for the singulation), are illustrated bythick dotted lines. As indicated in this example, each singulatedoptical module 50 produced this way can include, e.g., two channels,each channel including one active optical component 2 and (optionally)one passive optical component 9. Single-channel optical modules or stillother modules can of course be produced in a corresponding way.

In the singulation step, substrate 3 can transform into substrate parts49 a. Singulation can be accomplished by means of dicing, e.g., using adicing saw. Other ways of accomplishing the singulating can be applied,e.g., laser cutting.

During singulation, a temporary layer, such as, e.g., an adhesive tape,can be applied to the wafer, e.g., to the wafer's face oppositesubstrate 3. Accordingly, the temporary layer can adhere to at leastpart of the opaque coating 23. Singulation can then take place from thesubstrate-side of the wafer, such that stresses to which opaque coating23 is exposed during singulation, e.g., mechanical stresses from dicingwith a dicing saw, are low.

The temporary layer can be a tape and more particularly an adhesive tapesuch as, e.g., a UV tape which strongly reduces its adhering propertywhen exposed to UV light.

If, as proposed in an option, the substrate 3 is attached to carrierwafer 6 during most manufacturing steps, e.g., via tape 65, substrate 3(or rather wafer 1 g and 1 h, respectively) will be removed therefrombefore singulation in order to enable a transfer from carrier wafer 65(or, e.g., from tape 65) to temporary layer 68. This is symbolized incross-sectional FIGS. 13A and 13B. In FIG. 13A is illustrated thatcarrier assembly 66 including wafer 1 g (which is illustrated in astrongly simplified fashion, and which also could be, in anotherembodiment, wafer 1 h) is attached to temporary layer 68. During this,temporary layer 68 can be attached to a wafer frame 69 which can bering-shaped. Then, tape 65 (and therewith carrier 6) is removed fromwafer 1 g, e.g., by strongly reducing the adhering property of tape 65by heat.

FIG. 13B illustrates the situation after removal of carrier wafer 6 andafter singulation. Accordingly, a wafer-level arrangement 55 ofsingulated optical modules 50 is attached to temporary layer 68. Thesmall arrows indicate places where separation is accomplished. Substrateparts 49 (not specifically indicated in FIGS. 13A, 13B) are facing awayfrom temporary layer 68.

After singulation, the temporary layer 68 can be removed from the wafer,e.g., including irradiation with UV light.

Before a removal of the temporary layer 68 from arrangement 55, anauxiliary layer 53 (cf. FIG. 10), such as an adhesive tape, can beapplied to the opposite side of the wafer, i.e. to substrate parts 49 a.

This way, relative positions of the singulated optical modules (and thusthe wafer-level arrangement of singulated optical modules) can bepreserved despite removal of the temporary layer 68.

In some cases, it can be desirable that the final product includes aspectral filter.

E.g., the spectral filter can be present at least in all the apertures25. This way, light emitted by and detected by the active opticalcomponents 2, respectively, can be filtered by the spectral filter layerwhen passing through the respective aperture 25.

It is possible to apply a spectral filter layer to the wafer alreadyprior to singulation. In that case, the application of the spectralfilter layer can be accomplished after applying the heat treatment forthe strengthening the adhesion of the opaque coating 23 to the clearencapsulation material 8 or, alternatively, before such a heattreatment—if such a heat treatment is applied.

However, it is also possible to apply a spectral filter layer aftersingulation.

FIG. 10 depicts in a cross-sectional view a detail of a wafer-levelarrangement 55 of singulated optical modules 50 on which a spectralfilter layer 52 is present. Portions of spectral filter layer 52 whichcan possibly be present at or between side walls 30 are not drawn inFIG. 10.

In the wafer-level arrangement 55 of singulated optical modules 50, gaps56 between neighboring singulated optical modules 50 are present. Theycan be due to the singulation process. Each of the singulated opticalmodules 50 can have an opaque wall structure 54 which can includevertically oriented walls (which can form opaque side walls of thesingulated optical modules 50), which can be made of portions 51 ofopaque encapsulation material 31 and/or which can delimit the gaps 56.Side walls 30 of the intermediate products 28 can be covered by theportions 51 of the opaque encapsulation material 31.

Application of spectral filter layer 52 can be accomplished, e.g., byspray coating, or by spinning, or in other ways. In particular whenapplying spectral filter layer 52 after singulation, spray coating canpossibly be more suitable than spinning.

It is possible to apply spectral filter layer 52 selectively to theapertures 25.

Spectral filter layer 52 can let pass light in one or more specificwavelength ranges while blocking, e.g., absorbing, light in otherwavelength ranges. E.g., it can be provided that spectral filter layer52 is translucent for light of a particular range of wavelengths emittedby or detectable by the active optical components 2.

For example, spectral filter layer 52 can be an IR filter, and passiveoptical components 2 are operable to emit IR light and/or are operableto detect IR light.

A thickness of spectral filter layer 52 can be, e.g., between 0.5 μm and50 μm, such as between 1 μm and 20 μm, e.g., between 1 μm and 10 μm.

After application of spectral filter layer 52 onto the wafer or onto thewafer-level arrangement 55 of singulated optical modules 50, spectralfilter layer can be hardened, e.g., cured. The hardening can beaccomplished by, e.g., irradiation of spectral filter layer 52, e.g.,with UV radiation. Alternatively or in addition, a heat treatment or adrying step can be applied for accomplishing the hardening.

In connection with steps described above, one can, as an example andwith reference to FIG. 10, produce a wafer-level arrangement 55 ofsingulated optical modules 52, wherein it is ensured by, e.g., anauxiliary layer 53 applied to the substrate-sides of the optical modules50 that the singulated optical modules 50 remain in fixed relativepositions during producing the singulated optical modules. Then,spectral filter layer 52 is applied to the wafer-level arrangement 55 ofsingulated optical modules 50, e.g., by spray coating. And then,spectral filter layer 52 is hardened, e.g., cured, e.g., by UVirradiation.

Applying and hardening spectral filter layer 52 after singulation(instead of before singulation) can reduce delamination problems and/orcrack formation.

After singulation, i.e. after producing singulated optical modules 50,e.g., in form of a wafer-level arrangement 55 of singulated opticalmodules 50, another heat treatment can be applied, which can be a finalheat treatment of the manufacturing process. If a spectral filter layer52 (cf. FIG. 10) is applied, this heat treatment can be applied afterapplication of the spectral filter layer 52.

By means of this heat treatment, the singulated optical modules 50 canbe thermally stabilized. Adherence between different materials can beimproved and/or mechanical stresses can be reduced and/or equilibratedbetween the different materials.

A temperature to which the singulated optical modules 50 are heatedduring this thermal treatment can be between 100° C. and 160° C., e.g.,between 115° C. and 150° C.

The temperature applied can be, e.g., at least as high as thetemperature applied for hardening the opaque encapsulation material 31.

The temperature applied can be, e.g., within 10° C. identical to thetemperature applied in the heat treatment for strengthening the adhesionof the opaque coating 23 to the clear encapsulation material 8.

The heat can be applied for a duration of between 30 min and 240 min,e.g., for between 60 min and 180 min.

The heat can be applied, e.g., for between 2 times and 15 times, such as3 times and 10 times the time during which the heat for strengtheningthe adhesion of the opaque coating 23 to the clear encapsulationmaterial 8 is applied.

An automated optical inspection (AOI) can be accomplished, e.g., afterthe last one of the above manufacturing steps which is carried out.E.g., AOI can be applied to a wafer-level arrangement 55 of singulatedoptical modules 50 (with or without spectral filter layer 52 applied).

Several steps and/or sequences of steps are particularly designed forthe manufacture of very thin wafers, and in the case that the wafers areprevailingly made of polymer-based materials, e.g., more than 50% oreven more than 70% of the wafer volume can be polymer-based materials.Under such circumstances, special care must be and has been taken of thematerial properties such as of the CTEs of the polymer-based materials(which in instances are relatively high when compared to CTEs of metalsor semiconductor materials typically used) and of their humidity uptakeand their consequential expansion (which can also be relatively high).Also shrinkage of materials during hardening, in particular duringcuring, must be and has been considered, at least in instances.

For example, instead of trying to force the wafer to be completely flatduring all processing steps, it is suggested that the wafer is allowed,to some extent, to show warpage, which is enabled by using resilientmaterials such as by resilient molds and/or attached resilient layers.

And, as another example, heat treatments are, where possible, postponedtowards the end of the manufacturing process (possibly to aftersingulation) and/or are separated into separate heat treatments, whilebetween the separate heat treatments, mechanical stress is reduced,e.g., by segmenting the substrate and/or by singulation.

Furthermore, manufactured devices can be devoid any hollows and gasinclusions.

FIG. 11 is a flow chart of an example of the before-described method,wherein not all options are explicitly illustrated in FIG. 11.

Optional step 100 can relate to, e.g., mounting the active opticalcomponents on the substrate. Step 101 concerns the provision of theinitial wafer. Optional step 105 can relate to, e.g., the provision ofthe resilient encapsulation. Step 105 can additionally or alternativelyrelate to attaching the initial wafer to the carrier wafer and/or to atransfer of the initial wafer from the initial tape to the carrierwafer, e.g., by means of the special vacuum chuck described hereinbefore. In step 110, the clear encapsulation is applied. Optional step115 can relate to, e.g., the creating of the stepped structure. Step 120concerns the application of the opaque coating material onto the clearencapsulation. In step 130, the structuring of the opaque coatingmaterial to produce the opaque coating including the apertures. Step 140concerns the creation of the trenches extending through clearencapsulation material and the establishing of the side walls, so as toproduce the wafer-level arrangement of intermediate products, whereineach intermediate product has side walls. Step 150 concerns theapplication of the opaque encapsulation to the intermediate productsincluding filling the trenches with the opaque encapsulation material.Optional step 155 can relate to, e.g., the provision of the furrows inthe opaque encapsulation and/or to the heat treatment for, e.g., thepurpose of strengthening an adhesion of the opaque coating to the clearencapsulation material. Step 160 concerns cutting through the opaqueencapsulation material present in the trenches to produce the singulatedoptical modules, wherein each singulated product includes anintermediate product, and wherein the side walls of each intermediateproduct is covered by the opaque encapsulation material. Optional step165 can relate to, e.g., the application of the spectral filter and/orto the heat treatment which can be the final treatment of the methodand/or the AOI step.

The optical devices that can be manufactured by the describedmanufacturing method can include the described singulated opticalmodules 50. They can, e.g., be identical therewith.

In the following, some exemplary optical devices will be described,wherein they correspond to singulated optical modules. However, it willbe appreciated that many further kinds of optical devices can bemanufactured according to the described method, depending on which stepsare carried out and which steps are omitted, respectively.

FIG. 12A depicts in a cross-sectional view a single-channel opticaldevice 60 which includes no passive optical component and without stepstructure of the clear encapsulation and wherein opaque coating 23 andopaque encapsulation 32 are merely abutting.

The optical device 60 includes a substrate part 49 a, an active opticalcomponent 2, an opaque wall structure 54 (made of opaque encapsulationmaterial 31, cf., e.g., FIGS. 8-10) and an opaque coating 23 (made ofopaque coating material 24) which defines an aperture 25. It furthermoreincludes clear encapsulation material 8 which is surrounded by opaquewall structure 54 (sideways), opaque coating 23 (on top) and substratepart 49 a (below). In the illustrated example, active optical component2 is mounted on substrate part 49 a and electrically connected theretoby, e.g., a wirebond 4. Active optical component 2 is encapsulated byclear encapsulation material 8. This can also be considered anovermolding of active optical component 2 by clear encapsulationmaterial 8. Under the assumption that also substrate part 49 a is opaque(as always herein, in the sense that it is opaque for light of aparticular range of wavelengths emitted by or detectable by the activeoptical component 2), clear encapsulation material 8 is completelyopaquely covered (by opaque wall structure 54, opaque coating 23 andsubstrate part 49 a) with the aperture 25 as only exception. Clearencapsulation material 8 and active optical component 2 can belight-tightly enclosed in the described way—and thus with the exceptionof aperture 25.

When describing the section of the initial wafer finally included in anoptical device, instead of referring to the substrate part 49 a and theat least one active optical component 2 (wherein the at least one activeoptical component 2 can optionally be included in the substrate part 49a), it is also possible to state that the section of the initial waferincludes a substrate member 61 and, in addition, the at least one activeoptical component 2. In this terminology, the substrate member 61 can beidentical with the substrate part 49 a, if the substrate part 49 a doesnot include the at least one active optical component 2, and it can beidentical with the substrate part 49 a without the at least one activeoptical component 2, if the substrate part 49 a includes the at leastone active optical component 2.

The substrate member 61 can include two opposing and mutually parallelmember surfaces (which lie in lateral planes). A surface area of thesemember surfaces can be larger than a surface area of any other surfaceof the substrate member 61.

The substrate member 61 can include a multitude of openings. This can bethe case, e.g., when the at least one active optical component 2 isincluded in the substrate part 49 a. Cf. e.g., FIG. 12D and,correspondingly, FIGS. 1B and 1D.

The openings can, e.g., extend from the one to the other member surface.

In an alternative, the substrate member 61 can be devoid any openings.This can be the case, e.g., when the at least one active opticalcomponent 2 is not included in the substrate part 49 a. Cf. e.g., FIGS.12A-C and 12E-G and, correspondingly, FIGS. 1A and 1C.

In the optical device 60 of FIG. 12A, substrate part 49 a has, where itabuts opaque wall structure 54 (or more precisely: in a laterallydefined region where it abuts opaque wall structure 54), a thickness D2which is reduced with respect to its thickness D1 laterally betweenopaque wall structure 54; e.g., an average thickness of substrate part49 a where it abuts opaque wall structure 54 can be smaller than anaverage thickness it has laterally between opposing walls of opaque wallstructure 54. This can be due to producing trenches 27 (cf. FIG. 7)which not only extend fully through the clear encapsulation material 8,but also (and only partially) into substrate 3 and thus into substratepart 49 a. This feature can be present in any of the optical devices,also in cases where not depicted in the following respective figure(such as in FIGS. 12E to 12G).

FIG. 12B depicts in a cross-sectional view an optical device 60 whichcorresponds to the one of FIG. 12A, but it differs therefrom in thatactive optical component 2 is resiliently encapsulated by a resilientencapsulation material 7 (compare also FIG. 2). This feature can bepresent in any of the optical devices, also in cases where not depictedin the following respective figure.

FIG. 12C depicts in a cross-sectional view an optical device 60 whichcorresponds to the one of FIG. 12A, but it differs therefrom in that apassive optical component 9 is established by the clear encapsulationmaterial 8. This feature can be present in any of the optical devices,also in cases where not depicted in the following respective figure.

Passive optical component 9 and aperture 25 can be laterallyoverlapping. They can be, e.g., laterally centered with respect to oneanother.

FIG. 12D depicts in a cross-sectional view an optical device 60 whichcorresponds to the one of FIG. 12C, but active optical component 2 isincluded in a substrate part 49 a originating from a substrate 3 whichincludes an artificial wafer, cf. FIG. 1B. Substrate part 49 a can inthis case include active optical component 2 and a part 5 a of aninterconnection frame 5 of the artificial wafer, cf. FIG. 1B.

This feature can be present in any of the optical devices, also in caseswhere not depicted in the following respective figure.

Of course, optical devices can also be produced based on other initialwafers and correspondingly different substrates 3, cf., e.g., FIGS. 1Cand 1D besides FIGS. 1A and 1B.

FIG. 12E depicts in a cross-sectional view an optical device 60 whichcorresponds to the one of FIG. 12A, but it differs therefrom in that theclear encapsulation is stepped, as indicated at 18 designating a step.Opaque coating material 24 is not flat, like in FIG. 12A, but isstepped, too, as indicated at 18 designating a step in the opaquecoating 23.

In FIG. 12E, opaque encapsulation material 31 and opaque coatingmaterial 24 are mutually overlapping. Thus, in a laterally definedregion, both, opaque encapsulation material 31 and opaque coatingmaterial 24 are present.

Said region can, e.g., describe a closed shape, e.g., a ring (wherein aring does not need to be circular, but can describe, e.g., a rectangularline).

Walls of opaque wall structure 54 can exhibit, in a verticalcross-section, an L-shape, e.g., like illustrated in FIG. 12E.

Of course, an optical device 60 like the one of FIG. 12E can also bemanufactured to include a passive optical component, such as, e.g., inFIG. 12C or 12D.

Such an optical device 60 is illustrated in FIG. 12F, including passiveoptical component 9, wherein in addition, a spectral filter layer 52 isincluded in the optical device 60. Spectral filter layer 52 covers atleast a region laterally defined by the aperture 25. As illustrated inFIG. 12F, it can fully cover an upper side of the optical device 60.Said upper side can be opposite the substrate part 49 a.

FIG. 12G depicts in a cross-sectional view a dual-channel optical device60 which includes one passive optical component 9 per channel and has inboth channels a step structure of the clear encapsulation. The opticaldevice 60 of FIG. 12G can be understood as a dual-channel version of thesingle-channel optical device of FIG. 12F, only that the optionalspectral filter layer 52 is omitted in FIG. 12G.

While in the single-channel optical devices depicted before, all wallsof opaque wall structure 54 (made of opaque encapsulation material 31)can form opaque side walls which can be outer walls of the respectiveoptical device, in dual-channel (or even more-channel) optical devices60, like in the one illustrated in FIG. 12G, opaque wall structure 54can include (opaque) walls 54′ in addition to (opaque) walls 54″.Therein, the walls 54′ are inner walls of the optical device whichoptically separate the channels, while the walls 54″ are outer walls ofthe optical device.

Opaque walls 54′ can exhibit, in a vertical cross-section, a T-shape,e.g., like illustrated in FIG. 12G. The T-shape is still (substantially)a T-shape, also in case a split or a cut 48 is present in the wall.

Of course, also dual-channel (or even more-channel) optical devices 60,can include a substrate part 49 a having, where it abuts one of the(opaque) walls (54 or 54′), a thickness which is reduced with respect toits thickness laterally between walls 54 and/or 54′, similarly asillustrated in FIGS. 12A and 12B.

Optical devices with walls 54′ can include cuts 48 (cf. FIG. 12G andalso FIG. 9). Such cuts 48 can extend into (but not through) opaquewalls 54′. The cuts 48 can be located at a top end of a wall 54′, thetop end facing away from the substrate member 61.

In FIG. 12G, a coordinate system indicating lateral directions x, y andvertical direction z is sketched which is applicable also to the othercross-sectional views.

As described, a manufactured optical device can include on an upper faceof the clear encapsulation material 8 (which can be opposite thesubstrate part 49 a) an opaque coating 23 which is photostructurable andparticularly thin, while it can include outer walls (opaque wallstructure 54) made of an opaque encapsulation material 31 which can havea thickness which is at least 5 times, e.g., at least 10 times, ininstances even at least 20 times as large as the thickness of the opaquecoating 23. The opaque encapsulation material 31 can be, e.g., notphotostructurable.

The opaque encapsulation material 31 can be provided for improving amechanical stability of the optical device, while the opaque coating 23can be provided for defining the aperture 25.

An optical device can include

-   -   a substrate member;    -   one or more active optical components operable to emit or sense        light of a particular range of wavelengths;    -   a clear encapsulation material translucent to light of the        particular range of wavelengths;    -   an opaque coating material opaque for light of the particular        range of wavelengths, defining at least one aperture associated        with the one or more active optical components;    -   an opaque wall structure made of an opaque encapsulation        material opaque to light of the particular range of wavelengths.

The one or more active optical components 2 can be attached to thesubstrate member 61. In some embodiments, it can be placed ontosubstrate member 61, cf., e.g., FIGS. 12A-12C, 12E-12G and,correspondingly FIGS. 1A, 1C. In other embodiments, it can be integratedin and/or laterally surrounded by substrate member 61, cf., e.g., FIG.12D and, correspondingly FIGS. 1B, 1D.

The clear encapsulation material can establish an overmold for the oneor more active optical components 2. Cf., e.g., FIGS. 12A-12G.

The clear encapsulation material can establish an overmold for at leasta portion of the substrate member. Cf., e.g., FIGS. 12A-12G.

The opaque coating material 31 can be present on a surface of the clearencapsulation material 5, wherein said surface can be opposing anothersurface of the clear encapsulation material 5 facing the substratemember 61. Cf., e.g., FIGS. 12A-12G.

The opaque wall structure 54 can be a single-piece molding part. Cf.,e.g., FIGS. 12A-12G.

The opaque wall structure 54 can interface the substrate member 61, theclear encapsulation material 8 and the opaque coating material 24. Cf.,e.g., FIGS. 12A-12G. If present, it can interface the resilientencapsulation material 7, too, cf. FIG. 12B.

A maximum distance of opaque encapsulation material of the opaque wallstructure from a plane defined by the substrate member 61 can be equalto a maximum distance of opaque coating material from said plane, cf.,e.g., FIGS. 12A-12G. An exemplary plane is illustrated in FIG. 12G by adotted line, and said distance is illustrated by the dotted double-endedarrow. The plane is a vertical plane. And the plane can run through thesubstrate member 61.

This can be in contrast to constructing optical devices with separateaperture wafers and spacer wafers between aperture wafer and substratewafer known from prior art; in such cases, walls can be established bythe parts of the spacer wafer, and apertures can be established by partsof the aperture wafer, and the maximum distance of the aperture-bearingpart (part of aperture wafer) to said plane is larger than the maximumdistance of the side-wall-establishing part (part of spacer wafer) tosaid plane. It is typically larger by the thickness of the aperturewafer.

Furthermore, a vertical extension of the opaque coating material canoverlap with a vertical extension of the opaque encapsulation materialof the opaque wall structure. E.g., a vertical extension of the opaquecoating material can be included in a vertical extension of the opaqueencapsulation material of the opaque wall structure. And, a verticalextension of the opaque coating material can terminate together with avertical extension of the opaque encapsulation material of the opaquewall structure. Examples for all this are shown, e.g., in FIGS. 12A-12G.

The optical device 60 can be devoid any hollow inclusions. Cf., e.g.,FIGS. 12A-12G. The term hollow inclusion is meant to say that theinclusion contains a vacuum or a gas or a liquid and is completelysurrounded by solid material. This can contribute to an enhancedmanufacturability and to an improved stability and durability of theoptical device 60.

So far, with reference to the Figures, methods and devices have beendescribed under the assumption that the spectral filter layer materialis applied after singulation. In the following, the “other variant” ofthe invention already introduced before will be described with referenceto further Figures. In this “other variant”, no opaque encapsulationmaterial is applied (cf. item 24 in FIGS. 6A-6D), but a spectral filterlayer material is applied onto the clear encapsulation and structured toproduce a spectral filter layer. Accordingly, features related to theopaque coating need not be provided in the “other variant”. Otherwise,the methods and optical devices according to the “other variant” canhave the same features as described elsewherein herein.

FIG. 14 shows, in a cross-sectional view, a clear encapsulation wafer onwhich spectral filter layer material 52′ is applied. The clearencapsulation material 8 can be unstructured, having a planar surface(as illustrated in FIG. 14) on which the spectral filter layer material52′ is applied. Alternatively, the clear encapsulation material 8 can bestructured, e.g., like in FIG. 4 or in FIG. 5A or in FIG. 5C. However,depressions/protrusions 17, steps 18 or grooves 19 (cf. FIGS. 5A, 5C)can be dispensed with because their function of avoiding delamination ofopaque coating material 24 (cf. FIG. 6A) is superfluous since no opaquecoating material is applied in the “other variant”. But passive opticalcomponents (such as passive optical components 9 in FIG. 3) can beprovided, and will merely not be illustrated in the following Figures.

Application of spectral filter layer material 52′ can be accomplished,e.g., by spray coating, or by spinning, or in other ways.

A spectral filter layer is then produced by structuring the appliedspectral filter layer material 52′, which can be accomplished using aphotolithographic technique. This can make possible to achieve a highprecision of shape and position of structures, such as of apertures.

E.g., the spectral filter layer material 52′ can be selectivelyilluminated, e.g., using a mask or maskless, e.g., using direct laserwriting, and then, the illuminated (or the not-illuminated) spectralfilter layer material is removed, e.g., wet-chemically.

FIG. 15 shows, in a cross-sectional view, a clear encapsulation wafer onwhich such a spectral filter layer is present. E.g., the spectral filterlayer can include a multitude of patches of spectral filter layermaterial 52′. E.g., each of the patches can be associated with one ormore of the active optical components 2.

Spectral filter layer 52′ can let pass light in one or more specificwavelength ranges while blocking, e.g., absorbing, light in otherwavelength ranges. E.g., it can be provided that spectral filter layer52′ is translucent for light of a particular range of wavelengthsemitted by or detectable by the active optical components 2.

For example, spectral filter layer 52′ can be an IR filter, and passiveoptical components 2 are operable to emit IR light and/or are operableto detect IR light.

When the spectral filter material is present in all the apertures 25,light emitted by and detected by the active optical components 2,respectively, can be filtered by the spectral filter layer when passingthrough the respective aperture 25.

A thickness of spectral filter layer 52 can be, e.g., between 0.5 μm and50 μm, such as between 1 μm and 20 μm, e.g., between 1 μm and 10 μm.

Analogously to what is described above in conjunction with FIG. 7, in asubsequent step, a trenched wafer 1 f′ is produced like the one depictedin a cross-sectional view in FIG. 16. Trenched wafer 1 f′ is produced bycreating trenches 27, e.g., in the wafer of FIG. 15 which extend fullythrough the clear encapsulation. The trenches 27 can, as illustrated inFIG. 16, extend partially into substrate 3 (for better light tightnessof the produced optical devices).

The trenches 27 do not pass through the spectral filter layer material52′. Accordingly, special precautious measures against delamination ofthe spectral filter layer material 52′, like those taken for preventionof delamination of the opaque encapsulation, can be dispensed with incase of the presently described “other variant”.

Producing the trenches 27 (and side walls 30) can more specifically alsobe understood as producing a wafer-level arrangement 29 of intermediateproducts 28.

Analogously to what is described above in conjunction with FIG. 8, in asubsequent step, opaque encapsulation material 31 is applied.

FIG. 17 depicts in a cross-sectional view a detail of an opaqueencapsulation wafer 1 g′ which can be obtained by applying to a trenchedwafer 1 f′, such as to trenched wafer 1 f′ of FIG. 16, the opaqueencapsulation material 31. The trenches 27 created before (cf. FIG. 16)can be filled by the application of the opaque encapsulation material31.

FIG. 17 illustrates that opaque encapsulation material 31 can be appliedto the wafer-level arrangement 29 of intermediate products 28 depictedin FIG. 16.

In FIG. 17, opaque encapsulation wafer 1 g′ is depicted along with areplication tool 33 operable to shape opaque encapsulation material 31.

Like explained above for the shaping by replication of the clearencapsulation, also the opaque encapsulation can be shaped by means of areplication tool 33 including one or more side parts having a chamferedside shaping surface (cf. item 1 c in FIG. 4A). Likewise, this canprovide an improved anchoring of the opaque encapsulation to the clearencapsulation. This can reduce the exposure of the wafer to mechanicalstress.

Replication tool 33 can, as an option, include at least one resilientinner wall, such as resilient inner wall 34 in FIG. 8. In that case,replication tool 33 can also be referred to as a resilient replicationtool 33. In addition, replication tool 33 can include a rigid back as amechanical support for resilient inner wall 34, such as rigid back 37 inFIG. 8.

During shaping the opaque encapsulation material 31, a portion 47 a of asurface of the replication tool can be contact with the spectral filterlayer material 52′ in order to prevent opaque encapsulation materialfrom being deposited thereon. More concretely, the spectral filter layerhas top surfaces (in particular: each patch of spectral filter layermaterial 52′ can have one such top surface) facing away from the clearencapsulation material 8. Surface portions 47 a of the replication tool33 are, e.g., prior to applying the opaque encapsulation material 31,brought into contact with the top surfaces so as to seal the topsurfaces. The opaque encapsulation material 8 will then, e.g., by vacuuminjection molding, be applied to surround the spectral filter layer(and, e.g., each patch of the spectral filter layer material 52′) and bein sideways contact therewith, and despite of that, the top surfaces ofthe spectral filter layer remain uncovered by the opaque encapsulationmaterial 8, like illustrated in FIG. 17.

This way, apertures defined by the spectral filter layer are providedwith (perfectly) mating aperture stops established by the opaqueencapsulation, and the apertures themselves remain free from thespectral filter layer material 52′. Accordingly, the apertures remaindefined (with high precision) by the spectral filter layer. Andhigh-precision aperture stops are readily produced.

Replication tool 33 together with the spectral filter layer shape theopaque encapsulation material 52′.

Replication tool 33 can be unstructured, i.e. flat. This way, lateralalignment requirements of the replication too 33 with respect to thespectral filter layer are very low.

Alternatively, it can be provided that replication tool 33 isstructured, e.g., so as to include a multitude of protrusions, whereinthe protrusions (which can, e.g., include the surface portions 47 a) canbe planar, e.g., like illustrated in FIG. 17. A lateral extension ofeach of the protrusions can exceed a lateral extension of associatedportions of the spectral filter layer, in all lateral directions. Thisway, relatively relaxed lateral alignment requirements for thereplication tool 33 with respect to the spectral filter layer areachievable.

As symbolized in FIG. 17 by the open arrow, replication tool 33 (or morespecifically in some embodiments: of a resilient inner wall ofreplication tool) is pressed against trenched wafer 1 f′ duringapplication of the opaque encapsulation material 31, and morespecifically, surface portion(s) 42 a is/are in full direct contact withtop surfaces of the spectral filter layer.

The pressure applied can be due to an underpressure applied for the VIMprocess. Alternatively or in addition, further pressure can be applied(externally). This way, surface portion(s) 42 a and the top surfacescan, together, form a seal, wherein the seal cannot be crossed by opaqueencapsulation material 31 during its application to trenched wafer 1 f′.

By the protrusions of the replication tool 33, baffles can be produced(established by the opaque encapsulation material 31. Such baffles cancontribute to defining a field of view and field of illumination,respectively, for the active optical components 2 via the respectiveapertures. In addition, such baffles can contribute to protecting theapertures (and the spectral filter layer, respectively) from mechanicaldamage, simply because the baffles extend vertically beyond the spectralfilter layer.

Furthermore, in FIG. 17, cuts 48 are illustrated in dotted lines. Thoseoptional cuts 48, ways to produce them and their effects have alreadybeen described further above.

The arrows in the lower portion of FIG. 17 show where a subsequentsingulation can take place. For example, if separation is accomplishedat positions indicated by arrows with unbroken lines (and not atpositions indicated by arrows with dashed lines), multi-channel, e.g.,dual-channel optical devices can be produced; and if separation isaccomplished at positions indicated by any of the arrows (with unbrokenor with dashed lines), single-channel optical devices can be obtained.

FIG. 18 shows, in a cross-sectional view, a dual-channel optical device60 including no passive optical components. Of course, one or morepassive optical components, such as passive optical components 9 in FIG.12G, could be provided. Furthermore, the optical device 60 includes nobaffles. E.g., the opaque encapsulation can have been shaped using anunstructured replication tool, in contrast to the structured replicationtool 33 of FIG. 17 which would have resulted in optional baffles.

Optical device 60 can be, e.g., a proximity sensor.

Optical device 60 exhibits a wall structure of opaque encapsulationmaterial 31 including L-shaped walls 54″ and a T-shaped wall 54′.T-shaped wall 54′ is split by having a cut 48 in its middle top (wherethe two bars of the “T” meet).

Furthermore, a thickness of the substrate member 61 in a first region inwhich the opaque wall structure abuts the substrate member 61 is smallerthan a thickness of the substrate member 61 in a second region encircledby the first region. One or more active optical components 2 areattached in the second region to the substrate member 61.

Spectral filter layer material 52′ defines apertures and is laterallysurrounded by opaque encapsulation material 31 adjoining it (sideways).

FIG. 19 shows a flow chart of an example of a method for manufacturingoptical devices on wafer-level according to the “other variant” of theinvention. FIG. 19 is identical to FIG. 11 except that steps 120 and 130are replaced by steps 122 and 132. In step 122, the spectral filterlayer material is applied (cf. also FIG. 14). In step 132, the spectralfilter layer material is structured (cf. also FIG. 15).

The invention claimed is:
 1. An optical device comprising: a substratemember; one or more active optical components operable to emit or senselight of a particular range of wavelengths; a clear encapsulationmaterial translucent to light of the particular range of wavelengths,wherein the clear encapsulation material establishes an overmold for theone or more active optical components; a spectral filter layer materialstructured on a face of the clear encapsulation material so as to defineone or more apertures over and associated with the one or more activeoptical components each; an opaque encapsulation material opaque tolight of the particular range of wavelengths establishing an opaque wallstructure; an opaque coating opaque to light of the particular range ofwavelengths and which abuts the opaque encapsulation material, whereinthe opaque coating establishes one or more aperture stops, wherein theone or more aperture stops delimit the one or more apertures defined bythe spectral filter layer material; wherein the one or more activeoptical components are attached to the substrate member; wherein theclear encapsulation material is laterally surrounded by the opaque wallstructure, wherein the opaque coating is disposed above the clearencapsulation material; wherein each aperture is between walls definedby the opaque wall structure smaller than a spacing between the walls;and wherein the substrate member is disposed below the clearencapsulation material.
 2. The optical device according to claim 1,wherein the spectral filter layer material is translucent for light ofthe particular range of wavelengths.
 3. The optical device according toclaim 1, wherein the spectral filter layer material is opaque for lightof a range of wavelengths outside the particular range of wavelengths.4. The optical device according to claim 1, wherein the opaque wallstructure comprises at least one wall having a top end facing away fromthe substrate member, wherein at least one of the opaque encapsulationmaterial of the wall at the top end is split; a cut is present in thetop end of the wall.
 5. The optical device according to claim 1,comprising one or more passive optical components made of the clearencapsulation material.
 6. The optical device according to claim 1,wherein a thickness of the substrate member in a first region in whichthe opaque wall structure abuts the substrate member is smaller than athickness of the substrate member in a second region encircled by thefirst region.
 7. The optical device according to claim 1, comprising aresilient encapsulation material establishing an overmold for the one ormore active optical components, wherein the clear encapsulation materialestablishes an overmold for the resilient encapsulation material.
 8. Theoptical device according to claim 1, wherein the opaque wall structurecomprises at least one wall exhibiting an L-shape in a cross-section. 9.The optical device according to claim 1, wherein the opaque wallstructure comprises at least one wall exhibiting substantially a T-shapein a cross-section.
 10. The optical device according to claim 1, whereinthe substrate member is opaque to light of the particular range ofwavelengths, and wherein the optical device comprises an enclosure whichis light-tight for light of the particular range of wavelengths with theexception of the one or more apertures, the enclosure comprising atleast a portion of the substrate member and at least a portion of theopaque encapsulation material, and wherein the one or more activeoptical components are located inside the enclosure.
 11. The opticaldevice according to claim 1, wherein the optical device is a proximitysensor.